Resilient Foundations, Green Futures FINAL REPORT 2025 A ROADMAP FOR LOW INCOME HOUSING IN INDONESIA DISCLAIMER This work is a product of the staff of The World Bank with external contributions. The findings, interpretations, and conclusions expressed in this work do not necessarily reflect the views of The World Bank, its Board of Executive Directors, or the governments they represent. The World Bank does not guarantee the accuracy of the data included in this work. The boundaries, colors, denominations, and other information shown on any map in this work do not imply any judgment on the part of The World Bank concerning the legal status of any territory or the endorsement or acceptance of such boundaries. The World Bank does not necessarily own each component of the content contained within the work and does not warrant that the use of any third-party owned individual component or part contained in the work will not infringe on the rights of those third parties. Rights and Permissions The material in this work is subject to copyright. Because The World Bank encourages dissemination of its knowledge, this work may be reproduced, in whole or in part, for non-commercial purposes if full attribution to this work is given. Any queries on rights and licenses, including subsidiary rights, should be addressed to World Bank Publications, The World Bank Group, 1818 H Street NW, Washington, DC 20433, USA; fax: 202-522-2625; e-mail: PUBRIGHTS@WORLDBANK.ORG. Citation Please cite the report as follows: World Bank. 2025. “Resilient Foundations, Green Futures: Green Roadmap for Low-Income Housing in Indonesia”. Washington, DC: World Bank. 2 ACKNOWLEDGMENTS This report reflects five years of World Bank engagement in Indonesia's affordable housing sector, grounded in extensive field research and implementation experience under the National Affordable Housing Program. The report benefits from the close collaboration and partnership of the Ministry of Housing and Settlements (MoHS), previously Ministry of Public Works and Housing (MPWH), especially Mr. Haryo Bekti Martoyoedo, Director of Financing System Development for Housing and Settlement Areas and Ms. Fitri Ami Handayani, Head of Sub-directorate for Utilization of Funding Sources and Regional Financing System, Directorate General of Governance and Risk Management. This report was made possible through funding from The Korea Green Growth Trust Fund (KGGTF), which supports analytical work on carbon credit baseline, thermal resilience for low-income housing, and other green housing initiatives. Additional work referenced in this report was supported by various trust funds, as listed below: • Australia-World Bank Indonesia Partnership (ABIP): Advancing rooftop solar photovoltaic (RSPV) integration strategies (2023-2024) • Energy Sector Management Assistance Program (ESMAP): Piloting a climate-auction model and analyzing incremental green construction costs (2020-2021); supporting green certification systems (2023-2024) • City Climate Finance Gap Fund (Gap): Conducting the Palembang study on green home improvement and retrofit approaches (2021-2022) The report was prepared by a team led by Dao H. Harrison (Sr. Housing Specialist, IEAU2) and was co-authored by Daniel Caesar Pratama, Alfana Ayu Zahrafa, and Nida An Khofiyya (Consultants, IEAU1) with inputs from Harish Surendra Khare (Consultant, IEAU1). The work was carried out under the overall guidance of Bjorn Philipp (Practice Manager, IEAU1). Chapter 2.1 on combatting extreme heat and passive cooling design solutions benefitted from the team's collaboration with Fathina Izmi Nugrahanti from ITB and Habitat for Humanity- Indonesia. Chapter 3.2 on exploring rooftop solar panel was largely based on research of Castalia Consulting, working closely with Bipul Singh (Sr. Energy Specialist, IEAI1). Chapter 4.2, especially on carbon credit assessment, was supported by Keisuke Iyadomi (Senior Climate Change Specialist, SCCSK) and Sandeep Kanda (Consultant, SCCFE). The report received editorial support from Olivia Nielsen from Miyamoto International. Administrative support was provided by Nola Safitri (Program Assistant, EAITL). The team was fortunate to receive inputs from the following peer reviewers: Ana Campos Garcia (Lead DRM Specialist, IDURM), Keiko Sakoda (Sr. DRM Specialist, IDURM), Catherine Lynch (Senior Urban Specialist, IAWU4), and Griya Rufianne (Urban Specialist, IEAU1). Additional comments were received from Nicholas Jones (Data Scientist, IDURM), Vasudevan Rajasekharan Kadalayil (Consultant, IDURM), Daniel Zepeda (Consultant, IDURM), and Ian Taylor (Consultant, IDURM). RESILIENT FOUNDATIONS, GREEN FUTURES 3 ACRONYMS ABIP Australia-World Bank Indonesia Partnership AC Air Conditioner AIIB Asian Infrastructure Investment Bank API Application Programming Interface ATR/BPN Kementerian Agraria dan Tata Ruang/Badan Pertanahan Nasional Republik Indonesia (Ministry of Agrarian Affairs and Spatial Planning) BAPPEDA Badan Perencanaan Pembangunan Daerah (Local Development Planning Agency) BAPPENAS Badan Perencanaan Pembangunan Nasional (National Development Planning Agency) BCA Bank Central Asia BGH Bangunan Gedung Hijau (Green Building) BMKG Badan Meteorologi, Klimatologi, dan Geofisika (Meteorology, Climatology, and Geophysical Agency) BNI Bank Negara Indonesia BNPB Badan Nasional Penanggulangan Bencana National (Agency for Disaster Countermeasure) BPIW Badan Pengembangan Infrastruktur Wilaya (Regional Infrastructure Development Agency) BPS Badan Pusat Statistik (Central Bureau of Statistics) BP TAPERA Badan Pengelola Tabungan Perumahan Rakyat (The People’s Housing Savings Management Agency) BP2BT Bantuan Pembiayaan Perumahan Berbasis Tabungan (Savings-based Housing Finance Assistance) BRI Bank Rakyat Indonesia BSN Badan Standardisasi Nasional (National Standardization Agency) BSPS Bantuan Stimulan Perumahan Swadaya (Self-Help Housing Assistance Program) BTN Bank Tabungan Negara BTPNS Bank Tabungan Pensiunan Nasional Syariah BUMN Badan Usaha Milik Negara (State-Owned Enterprise) CBO Community-Based Organization CMIRD Coordinating Ministry of Infrastructure and Regional Development EDGE Excellence in Design for Greater Efficiencies 4 ESMAP Energy Sector Management Assistance Program FLPP Fasilitas Liquiditas Pembiayaan Perumahan (Housing Finance Liquidity Facility) FTV Financing-to-Value Gap Fund City Climate Finance Gap Fund GBPN Global Buildings Performance Network GHG Greenhouse Gas GoI Government of Indonesia HVAC Heating, Ventilation, and Air Conditioning HMF Housing Microfinance IGAHP Indonesia Green and Affordable Housing Program IsDB Islamic Development Bank IDX Indonesia Stock Exchange IDR Indonesian Rupiah Jabodetabek Jakarta, Bogor, Depok, Tangerang, and Bekasi KLM Kebijakan Likuiditas Makroprudensial (Macroprudential Liquidity Incentive Policy) KOTAKU Kota Tanpa Kumuh (City Without Slums Program) KPR Subsidi Kredit Pemilikan Rumah Subsidi (Subsidized Mortgage Program) KUR Kredit Usaha Rakyat (People’s Business Credit) LTV Loan-to-Value MEMR Ministry of Energy and Mineral Resources MoEF Ministry of Environment and Forestry MoF Ministry of Finance MoHA Ministry of Home Affairs MoHS Ministry of Housing and Settlements MPW Ministry of Public Works MPWH Ministry of Public Works and Housing NAHP National Affordable Housing Program NDC Nationally Determined Contribution NEK Nilai Ekonomi Karbon (Carbon Economic Value) NGO Non-Governmental Organization NSUP National Slum Upgrading Project RESILIENT FOUNDATIONS, GREEN FUTURES 5 PBG Persetujuan Bangunan Gedung (Building Approval Permit) PLN Perusahaan Listrik Negara (State Electricity Company) PSC Program Steering Committee PSR Program Sejuta Rumah (One Million Homes Program) QAQC Quality Assurance / Quality Control RSPV Rooftop Solar Photovoltaics RPIM Rasio Pembiayaan Inklusif Makroprudensial (Macroprudential Inclusive Financing Ratio) SiKumbang Sistem Informasi Kumpulan Pengembang (Developer Housing Platform) SiPetruk Sistem Pemantauan Konstruksi Construction Monitoring System) SMF Sarana Multigriya Finansial (State-owned Secondary Mortgage Finance Company) SNI Standar Nasional Indonesia (Indonesian National Standard) Sertifikat Laik Fungsi SLF (Certificate of Proper Function/ Occupancy Certificate) SOP Standard Operating Procedure SUSENAS Survei Ekonomi Nasional (National Economic Survey) TOD Transit-Oriented Development tCO2e Tons of Carbon Dioxide Equivalent UMP Upah Minimum Provinsi (Regional Minimum Wage) USD United States Dollar WB World Bank 6 CONTENTS Figures 08 Tables09 Executive Summary 10 Summary of Actions & Key Recommendations 13 1 . Aligning Policy with Climate Realities  16 1.1 Introduction  17 1.2 Overview of the Affordable Housing Sector in Indonesia19 2. Climate Adaptation & Disaster Resilience Action Framework 24 2.1 Action A: Combating Extreme Heat with Passive Cooling Design Solutions 25 2.2 Action B. Promote Resilient Housing Design and Construction to Withstand Floods and Earthquakes 32 2.3 Action C: Risk-Informed Site Planning and Urban Design Strategies in Integrated Housing and Settlement Upgrading Project37 3. Climate Mitigation Action Framework 42 3.1 Action D: Cut Operational Energy and Material-Based Emissions 43 3.2 Action E: Explore Opportunities to Integrate Rooftop Solar Photo-Voltaic Panels into the Affordable Housing Sector 48 3.3 Action F: Beyond Individual Housing: Advancing Sustainability Through Neighborhood and City-Scale Systems52 4. Cross-Cutting Action Framework 57 4.1 Action G: Building Resilient and Green Housing Construction Permitting, Monitoring and Certification Systems 58 4.2 Action H: Enable Green Financing and Carbon Credit  65 5. Conclusion 69 5.1 Summary of Actions and Key Recommendations 71 Annexes74 Annex 1: Thermal Comfort Study for Low-Income Housing 75 Annex 2: Commonly Used Construction Materials in Housing Development 76 Annex 3: Government Housing Prototypes 77 Annex 4: Construction Quality Issues During National Affordable Housing Program 80 Annex 5: Classification of City/Towns Characteristics 82 Annex 6: Green Retrofit and Densification Study in South Sumatra  83 Annex 7: Institutional Silos in the Housing Sector 84 Annex 8: Calculation of GHG Emissions Reduction 86 References87 RESILIENT FOUNDATIONS, GREEN FUTURES 7 FIGURES Figure 1. Examples Of Simple-Non-Engineered Homes in BSPS Housing Program 19 Figure 2. Differences Between Climate Adaptation, Climate Mitigation, and Cross-Cutting Actions 23 Figure 3. Indonesia Heat Index 26 Figure 4. The Baseline Indoor Temperature Of Simple Non-Engineered House 27 Figure 5. Illustration of Intervention Models 28 Figure 6. Iboxplot Showing the Reduction in Indoor Temperature Compared to the Baseline Model A 29 Figure 7. Graph Showing the Temperature of Houses With Aluminum Foil Roof Insulation 30 Figure 8. Graph Showing the Temperature of Houses With Ceiling and Gable Ventilation 30 Figure 9. Graph Showing the Composite Technical Performance Score And Incremental Construction Cost 31 Figure 10. Proposed Roadmap for Adopting Green Passive Cooling Solutions Addressing Thermal Stress 31 Figure 11. KPR Subsidi Housing Complex In Bekasi Submerged in Flood Waters 33 Figure 12 Stilt House And Clamshell Waste as Porous Surface in Kampung Kerang Ijo 33 Figure 13. Example Of Retrofit Guideline And Common Construction Mistakes Developed by Build Change, World Bank, and Mohs for the IGAHP Pilot 34 Figure 14 Building Level Adaptation 36 Figure 15. Risk-Prone Layout With Single-Entry Access, Resilient Layout With Multiple Entry Points Enabling Redundancy and Safer Evacuation Routes 38 Figure 16. Traditional Bamboo Homes With Flexible Joints, Rigid Masonry Row Housing (Existing), Buffered Row Houses in Sumbawa 39 Figure 17. Flood Retention Park In Jakarta, Vegetated Embankment, Clean Drainage Channel in Kotaku 40 Figure 18. In Cieunteung, Participatory Design of a Retention Pond Created Recreational Benefits Alongside Improved Flood Management, Strengthening Maintenance and Community Pride 40 Figure 19. Electricity Use Profile in KPR Subsidi Homes 44 Figure 20. Energy Savings for Implementing Energy-Efficient Appliances (South Pole) 46 Figure 21. Example of Green Housing Prototypes Currently Being Developed by MOHS 47 Figure 22. Installed Capacity & Resource Potential by Island in Indonesia 49 Figure 23. Rooftop Rental Business Model 50 Figure 24. Map of RSVP Costs Across Indonesia 51 Figure 25. Average Residential Price Growth Comparison Between Subsidized Rate and Market Rate in Jabodetabek 52 Figure 26. Estimated Commuting-Related Housing Carbon Emissions 53 Figure 28. Missing Middle Housing in Indonesia 55 Figure 29. Comparison of Green Certification Systems 59 8 Figure 30. Schematic of Data-Driven and Risk-Informed Location Choice for Housing and Settlement Development 62 Figure 31. Proposed Schematic of Linking Location Analysis, Technical Proposal, PBG, SLF, and Green Certification Issuance for Government-Led Housing Developments 64 Figure 32. Green Housing Loans Growth by Type 66 TABLES Table 1. Summary of Climate and Disaster Adaptation Strategies by Scale and Hazard Type41 Table 2. Summary of Climate Mitigation Strategies by Scale 56 Table 3. Embodied Energy of Common Walls Materials From the Highest to Lowest Embodied Energy 76 Table 4. Embodied Energy of Common Roof Materials From the Highest to Lowest Embodied Energy77 Table 5. Prototypes initiated by MoHS still in development stage 79 RESILIENT FOUNDATIONS, GREEN FUTURES 9 EXECUTIVE SUMMARY Indonesia’s housing sector stands at the front line of a changing climate. The country is highly vulnerable to rising heat, intense Low-income housing units consume minimal energy and rainfall, sea-level rise, and seismic events. Located along contribute little to direct greenhouse gas emissions; however, the Pacific Ring of Fire, Indonesia faces some of the highest their design and construction leave them highly vulnerable seismic risks in the world, with frequent earthquakes and to climate hazards. Strengthening the built environment volcanic activity threatening housing stability and safety. to improve climate resilience in both existing and future With nearly 20% of the population living in low-elevation homes presents a significant opportunity. Enhancing coastal zones and projections indicating 116 million people safety, thermal comfort, and structural durability not only could be flood-exposed by 2030, climate adaptation in safeguards vulnerable households but also establishes a the housing sector is not optional—it is urgent. Indonesia scalable foundation for broader and sustained climate has committed to reducing emissions by 29% (41% mitigation efforts across the housing sector. with international support) by 2030 and achieving net- In the context of affordable housing, “green” must be zero by 2060. The building sector, as one of the largest reframed to put resilience at the core—not as an add-on, energy consumers, must therefore play a crucial role in but as the starting point. Currently, the green agenda in this transition. the housing sector centers largely on climate adaptation, Affordable housing, long a priority in Indonesia’s including emission reduction, renewable energy adoption, development agenda, is being positioned by the and the use of sustainable design and materials. Defining Government to advance the country’s green goals while green housing for low-income communities in Indonesia protecting vulnerable populations. Housing needs on solely in terms of climate-responsive, energy-efficient both quantitative and qualitative deficit are high, with 12 features is a stretch, given the widespread exposure to natural million households needing new housing (13.6% of total hazards and the structural limitations of most housing households) and 28.6 million households needing better stock. Low-income households often live in areas highly housing (36.8% of total households). Government-led vulnerable to extreme heat, flooding, and seismic activity— programs have collectively supported over a million new risks that are intensifying with climate change.3 As such, or improved homes. The Indonesia Green and Affordable green housing in Indonesia must first prioritize resilient Housing Program (IGAHP), initiated by the Ministry of construction that can withstand these environmental Housing and Settlement or MoHS (formerly Ministry of shocks. Only after these foundational vulnerabilities are Public Works and Housing or MPWH) in 20241 set a vision addressed should additional green features—such as low- for achieving net-zero homes by 2050 as a part of 2060 net- carbon materials, energy-efficient appliances, rooftop solar, zero NDC target. 2 and water-saving systems—be progressively introduced to support longer-term climate mitigation goals. 1 antaranews.com. ² World Bank provided technical assistance to MoHS to inform the development of IGAHP. 3 Asian Development Bank, “Building Resilience of the Urban Poor in Indonesia.” 10 Heat stress is now one of the most immediate and chronic using ferrocement technology. Yet, flood-adaptive housing threats to livability in low-income communities, requiring design remains under-researched and rarely implemented. urgent adoption of passive cooling design solutions to Strengthening and mainstreaming existing institutional protect household health and comfort. In densely built tools like SiKumbang7 and SiPetruk8, and aligning them neighborhoods with limited tree cover, homes are often with building permits and certification systems, is vital to constructed using heat-trapping materials like corrugated scaling resilience across the building life cycle. steel roofs, leading to indoor temperatures that regularly Effective climate mitigation in affordable housing is exceed safe and comfortable levels. Traditional self-built achievable without high-cost interventions. Modest designs have not evolved to mitigate rising heat risks. investments in passive design, green housing prototypes, However, a pilot study show that low-cost passive cooling and retrofit strategies can yield significant environmental design solutions such as aluminum foil insulation and gable and economic benefits. When combined with energy- ventilation can lower indoor temperatures by up to 2.35°C efficient appliances, low-emission materials, and scalable relative to outdoor temperatures while adding around 2-3 technologies like LED lighting and biofilter septic systems, million IDR to overall construction costs, significantly these approaches enhance performance while remaining improving household comfort and health.4 cost-effective. For example, meeting Bangunan Gedung Floods and earthquakes pose serious threats to both Hijau9 (BGH) “Madya” certification standards adds just lives and housing assets in Indonesia’s low-income 2.5 percent to construction costs but results in substantial communities. Although hazard maps and early warning lifetime savings on utility bills and lower emissions. systems exist, they are rarely integrated into spatial Among mitigation strategies for the affordable housing planning, permitting, or construction inspection processes. sector, rooftop solar photovoltaics (RSPV) present a The National Affordable Housing Program (NAHP)5 potential opportunity worth exploring and piloting. introduced standardized quality assurance and quality Indonesia’s affordable housing stock has the technical control (QAQC) systems that improved housing quality potential to generate up to 1.3 GW/year of solar energy. in the Bantuan Stimulan Perumahan Swadaya (BSPS) or A rooftop rental model, where utilities like PT PLN Icon Home Improvement program by seven (7) times from the Plus10 lease rooftops for solar panel installation, can unlock baseline, though enforcement remains weak for the FLPP this potential, especially for public rental and in peri-urban home ownership credit-linked subsidy program. Indonesia areas outside of the Java-Bali where grid electricity is has consistently worked to improve the seismic resilience costlier. For widespread adoption, homes must be clustered, of its built environment, beginning with its first seismic- roofs strengthened, and designs adapted to optimize solar resilient building regulations established in the 19656, efficiency and minimize shading. concurrent with new innovation developments such as 4 World Bank study (2025) in collaboration with Habitat for Humanity to test passive cooling designs in simple landed housing. 5 The National Affordable Housing Program, a World Bank USD 450 million program to support the GoI in improving access to affordable housing to lower income households. 6 Nugroho, Sagara, and Imran, “The Evolution of Indonesian Seismic and Concrete Building Codes.” 7 SiKumbang is an affordable housing developer database managed by BP Tapera. Developers participating in GoI’s KPR Subsidi programs are required to include their housing project information into SiKumbang. https://sikumbang.tapera.go.id/ 8 SiPetruk is a construction monitoring system for developer-built affordable housing managed by BP Tapera. The system requires developers to submit detailed project documentations to qualify for KPR Subsidi programs. The system was piloted in 2020 but has not been fully implemented to date. 9 BGH is the green certification system established in 2021 by the Ministry of Public Works and Housing, Directorate General of Cipta Karya (Human Settlement) 10 PT PLN Icon Plus is a subsidiary of PT PLN, Indonesia's state-owned electricity company. It focuses on providing telecommunications, information technology, and solutions to support PLN's business operations and expand into related sectors. RESILIENT FOUNDATIONS, GREEN FUTURES 11 Enabling a green transformation in the housing sector Finally, achieving scale demands financial incentives that requires strengthening the implementation of Indonesia’s make green construction viable for both developers and BGH certification system. While still at an early stage, households. Green finance instruments such as Bank BGH is expected to be the Government’s primary tool for Indonesia’s liquidity incentives and inclusive financing greening public housing programs and holds significant ratios can support demand and supply-side transformation. potential for broader adoption. However, this potential Pilot incentive schemes have shown positive responses can only be realized with stronger local government but also revealed critical bottlenecks in delivery systems, capacity, robust monitoring systems, and effective QAQC especially for retrofits. Scaling up will require partnerships frameworks. BGH must be integrated with the occupancy with mainstream commercial banks, stronger field certificate (Sertifikat Layak Fungsi, or SLF) process to ensure facilitation, and streamlined guidelines for green and compliance with minimum construction standards, support resilient compliance. While carbon credits are not yet the development of training and inspection systems, and financially viable for low-income housing, the increasing enable context-appropriate site assessments. use of air conditioning among low-income households signals a growing opportunity for future carbon finance, Impact of housing sustainability can be extended through especially if paired with climate-responsive passive design. neighborhood- and city-scale interventions. Shifting from low-density simple non-engineered homes toward more Indonesia’s transition to climate-resilient, low-carbon compact, multi-family housing can improve land use housing is both urgent and within reach. With committed efficiency, reduce car dependence, and facilitate shared Government leadership, strategic interventions, and energy and water infrastructure. Integrated urban planning cross-sector collaboration, the housing sector can play that leverage data-driven and risk-informed housing a transformative role in advancing climate adaptation location tools such as multi-criteria spatial analysis and and mitigation. Integrating resilience into core housing scenario planning, can guide housing development to programs, scaling affordable green solutions, reinforcing safer, more connected areas and reduce emissions linked institutional capacity, and unlocking green finance are to commuting and land conversion. Water-sensitive urban critical steps that will protect vulnerable communities and design and heat mitigation must be planned across scales, build a more sustainable, inclusive urban future. from household rain gardens and roof insulation to city- level forests and cool corridors. 12 SUMMARY OF ACTIONS & KEY RECOMMENDATIONS Climate Adaptation Recommendations: Embed resilience to climate shocks – such as flooding, earthquakes, and heat stress, into housing design, construction, and policy to safeguard lives, assets, and public investments. ACTIONS STRATEGIC RECOMMENDATIONS Scale up passive cooling interventions in Government housing ACTION A programs such as BSPS to protect vulnerable families against Combat Thermal Stress extreme heat. with Passive Cooling Gradually integrate passive cooling design into all Design Government programs to reduce energy demand and build the foundation for energy-efficient housing. Socialize passive cooling interventions through local government, NGO’s and communities to keep low-income communities safe. ACTION B Accelerate the implementation of earthquake-resilient simple Promote Resilient Housing building prototypes and earthquake-informed PBG and SLF Design and Construction issuance, especially for Government-led housing program. to Withstand Flood & Establish, integrate and monitor earthquake-resilient housing Earthquake retrofit guidelines in Government housing programs. Prepare guidelines to accommodate household incremental design and construction modification by occupants. Invest in flood-resilient housing research and flood-resilient building standard. ACTION C Embed disaster risk-responsive site planning into housing and Risk-Informed Integrated settlement design. Housing and Slum Implement neighborhood-scale design interventions to reduce Settlement Upgrading vulnerability to earthquakes, flooding, and thermal stress. Integrate physical interventions with community engagement and public awareness campaign. RESILIENT FOUNDATIONS, GREEN FUTURES 13 Climate Mitigation Recommendations: Build low-carbon, durable, and energy efficient housing to reduce emissions while strengthening resilience to long term energy and environmental shocks. ACTIONS STRATEGIC RECOMMENDATIONS ACTION D Prioritize low-embodied energy materials and implement Cut Operational Energy passive design principles at the design and construction stage. and Material-Based Revise the SNI11 standards for household electrical appliances Emissions to incorporate energy efficiency requirements and formalize the mandatory use of SNI-certified home appliances in the green building certification regulation. Formalize green housing prototypes and guidelines for simple non-engineered housing and government housing programs under the authority of the Government body overseeing construction. ACTION E Explore roof rental business models for RSPV utilization on Explore opportunities to public buildings, including large public housing. integrate Rooftop Solar Assess modification of low-income housing design in Photo-Voltaic Panel Government housing program to meet RSPV adoption technical criteria. Pilot RSPV for Government low-income housing design, especially for areas beyond Java-Bali grid. ACTION F Redesign Government-subsidized housing typologies to Advance Sustainability prioritize mid- to high-density formats that reduce land Through Neighborhood consumption and urban sprawl. and City-Scale Systems Promote compact urban forms and integrated sustainable mobility through TOD. Invest in communal and district-level infrastructure and renewable energy systems to achieve scale-efficient emissions reduction. 11 SNI is the official standardization system regulated by BSN (Badan Standardisasi Nasional) , the National Standardization Agency of Indonesia. SNI covers a wide range of sectors, including construction, materials, safety, and environmental standards, and is often mandatory for public infrastructure and building compliance. 14 Cross-Cutting Recommendations: Establish enabling systems through regulation, quality assurance, certification, and financing to support the verifiable and sustained delivery of green and resilient housing ACTIONS STRATEGIC RECOMMENDATIONS ACTION G Integrated design: seismic, flood, thermal resilient, and green Build resilient and green sustainable prototypes and retrofit guidelines, including housing construction universal accessibility requirements permitting, monitoring Implement risk-informed planning and permitting through and certification systems integrated spatial data to ensure location suitability and reduce household disaster exposure. Enforce housing construction quality through a robust QAQC system with the use of digital technologies and cross-agency coordination. Strengthen BGH certification system into a scalable and comprehensive assessment framework that aligns with international best practices. ACTION H Tackle structural barriers to expand demand for green Enable green financing housing finance by enabling developers and homeowners through simplified processes, awareness campaigns, and incentives. Unlock the housing sector’s carbon credit potential through dedicated regulations and large-scale, high-impact energy efficiency interventions. RESILIENT FOUNDATIONS, GREEN FUTURES 15 01 Aligning Policy with Climate Realities 16 1.1 INTRODUCTION 1.1.1 Climate Change & Disaster Context in living in low-elevation coastal zones, the fifth-largest Indonesia share globally, Indonesia faces heightened exposure to climate-related hazards.16 As of 2022, this vulnerability Climate change presents acute and escalating risks for translates to around 76 million people, or a quarter of the Indonesia. Even if global warming is limited to 1.5°C by population, living in high-risk flood zones.17 Annual flood mid-century, the country is expected to experience more damages, already impacting 1.5 million people and costing extreme heat, erratic rainfall, frequent droughts, sea-level $1.4 billion as of 2010, are projected to increase by $6.1 rise, and ocean acidification.12 These climate shifts pose billion and affect 400,000 more people annually due to serious risks to ecosystems, infrastructure, and the well- climate change. being of communities throughout the archipelago. Indonesia has committed to ambitious climate targets Indonesia is among the countries with the most exposure through its Nationally Determined Contributions (NDC). to extreme heatwaves. With average monthly maximum As one of the world’s leading coal producers and largest temperatures around 30.6°C, extreme heat is already a greenhouse gas emitters, Indonesia faces an urgent need reality. Climate projections suggest that by the end of the to accelerate its decarbonization efforts.18 By 2030, the century, Indonesia may experience extreme heatwaves as country aims to reduce emissions by 29% unconditionally, frequently as once every two years, with serious implications or by 41% with international support.19 The buildings for public health and economic productivity.13 sector, its third-largest energy consumer, has a target to Seismic and tsunami hazards amplify Indonesia’s exposure. reduce 27,780 metric tons of CO2 equivalent and achieve Located on the Pacific Ring of Fire, the country frequently net-zero emissions by 2060 or sooner.20 experiences earthquakes exceeding magnitude 6.0. As Low-income families are at the forefront of climate impacts. of mid-2023, Indonesia’s tsunami risk index was 9.7 out In Indonesia, 76 million people live in high-risk flood zones, of 10.14 This reinforces the urgency of making resilient with the majority (42.6 million) living in poverty.21 The housing a national priority. wealthiest 1% of Indonesia’s population are responsible for Flooding and sea-level rise compound Indonesia’s climate an average of 42.2 tons of CO2 equivalent (tCO2e) GHG vulnerability. Indonesia’s rising flood risks are being emissions per capita, over thirty times higher than the 1.4 intensified by rapid, unplanned urban expansion, which is tCO2e per capita emitted by its bottom 50%.22 While the projected to account for 87% of the increased coastal flood wealthiest 10% of the global population are responsible exposure.15 With approximately 18% of its population for approximately two-thirds of global greenhouse gas 12 Coalition for Urban Transitions, “Seizing Indonesia’s Urban Opportunity: Compact, Connected, Clean, and Resilient Cities as Drivers of Sustainable Development.” 13 Russo et al., “Magnitude of Extreme Heat Waves in Present Climate and Their Projection in a Warming World.” 14 Statista, “Indonesia.” 15 Kuzma (WRI) and Luo (WRI), “The Number of People Affected by Floods Will Double Between 2010 and 2030.” 16 World Bank Group and Asian Development Bank, Climate Risk Country Profile. 17 World Bank, “World Bank Approves Support to Improve Flood Resilience and Risk Management in Indonesia.” 18 globaldata.com, “Greenhouse Gas Emissions in Indonesia (2010 - 2021).” 19 UNFCCC, “Enhanced Nationally Determined Contribution - Republic of Indonesia.” 20 IKI_ALCBT_GGGI, “Low Carbon Buildings to Achieve Indonesia’s Climate Ambitions.” 21 World Bank, “Floods in the Neighborhood.” 22 Chancel et al., “World Inequality Report 2022.” RESILIENT FOUNDATIONS, GREEN FUTURES 17 emissions, the impacts of climate change disproportionately affect low-income communities worldwide. However, the impacts of climate change disproportionately affect low- income communities.23 These vulnerable populations often lack the resources to adapt to climate-related hazards such as extreme heat, flooding, and air pollution, leading to higher rates of illness and mortality. To tackle this imbalance, the Intergovernmental Panel on Climate Change (IPCC) highlights that the most effective urban climate action involves improving access to finance for low-income and marginalized communities, particularly those living in informal settlements, to reduce their climate risk.24 23 Fujii, “Climate Change and Vulnerability to Poverty: An Empirical Investigation.” 24 Calvin et al., “IPCC, 2023.” 18 1.2 OVERVIEW OF THE AFFORDABLE HOUSING SECTOR IN INDONESIA Indonesia contends with a persistent quantitative housing pronounced in cities like Jabodetabek, Bandung, Surabaya, deficit. The current quantitative housing backlog stands at and Medan. 12 million units, including an occupancy gap of 8 million The majority of Indonesian households live in simple non- and an additional annual demand of 1 million new units.25 engineered houses, often self-built residential structure Affordability remains the leading barrier to homeownership constructed without formal architectural or engineering in Indonesia, with over 63% of non-homeowners reporting oversight30. These homes typically use locally available financial constraints as the primary reason for not materials and traditional building techniques, lack purchasing or building a home.26 In urban areas, only the top structural calculations or compliance with minimum 30% of earners can afford homes priced at IDR 300 million construction standards, and are especially common in (US$19,300) or above without assistance.27 Middle-income low-income or informal settlements. While affordable and households (3rd–6th income deciles) require subsidies to rapidly built, they are often highly vulnerable to disasters access formal housing, while the bottom 20% depend on like earthquakes and floods due to poor structural integrity. significant Government support even for basic housing.28 Government efforts through the One Million Homes Indonesia’s qualitative housing deficit is even more acute. Program (PSR) have made progress but remain insufficient. As of 2022, approximately 28.6 million households, Launched in 2015, PSR aims to expand housing supply equivalent to nearly half of all households in Indonesia, through public and private financing. It has consistently were living in substandard housing.29 Housing insecurity, met its target of one million homes annually, delivering however, extends beyond low-income groups. Indonesia’s over 800,000 new units and renovating 200,000 each year growing middle class, estimated at over 115 million through direct government support and private-sector people, is also increasingly challenged by rising housing mechanisms. Still, this falls short of meeting the full scale costs and inadequate living conditions. With over 58% of annual demand and bridging the existing backlog. of the population living in urban areas, the deficit is most FIGURE 1. EXAMPLES OF SIMPLE-NON-ENGINEERED HOMES IN BSPS HOUSING PROGRAM (Source: pu.go.id) 25 Susenas. (2019, 2022). Modul Kesehatan dan Perumahan (MKP). 26 Perdamaian and Zhai, “Status of Livability in Indonesian Affordable Housing.” 27 World Bank, “Implementation Completion and Results Report - National Affordable Housing Program.” 28 World Bank Housing Task Team. (2023). Calculation of Housing Affordability Based on Income Levels in Indonesia. 28 Susenas (2019, 2022). 29 Susenas (2019, 2022). 30 UNESCO, “ Towards Resilient Non-Engineered Construction: Guide for Risk-Informed Policy-Making; 2016.” RESILIENT FOUNDATIONS, GREEN FUTURES 19 To address the housing deficit, the Government of Indonesia IGAHP aims to align housing development with climate implements three core initiatives under the One Million goals. Led by the Ministry of Housing and Settlement Homes Program. (MoHS) with World Bank technical support32, IGAHP seeks to scale green, resilient, and affordable housing by • Credit-linked subsidy programs (KPR Subsidi: FLPP, mobilizing private capital and reducing fiscal subsidy SSB, and BP2BT): Since 2010, the FLPP (Housing burdens. It envisions achieving 100% net-zero carbon for Finance Liquidity Facility) has provided affordable new housing construction by 2050 as a part of Indonesia’s mortgage financing for low-income households 2060 net-zero NDC target. for homeownership. From 2015 to 2020, the SSB (Interest Rate Subsidy) was introduced to further President Prabowo’s Three Million Homes significantly scale KPR Subsidi volume. From 2018 to 2023, the scaled up the national housing target and presents a vital BP2BT (Savings-based Housing Finance Assistance) opportunity to embed climate resilience and sustainability program offered down payment assistance through into large-scale housing delivery. In February 2025, the NAHP, expanding access for informal workers. President Prabowo announced the program, which aims The KPR Subsidi program delivers approximately to construct two million homes in rural areas and one 200,000 units annually, all constructed by private million in urban areas. In support of this bold initiative, developers following the same approach, regardless of this report provides a roadmap for integrating green and the type of government credit-linked subsidy provided. resilient design into the program—ensuring that as housing While formally required to adhere to minimum needs are addressed at scale, vulnerable populations are construction standards and obtain necessary building also safeguarded from disasters and the growing impacts permits (PBG), in practice, many KPR Subsidi houses of climate change. fail to meet minimum construction standards. 31 • BSPS (Home Improvement Grant Program): Running 1.2.1 Integrating Climate Concerns into the since 2006, BSPS targets the qualitative housing Affordable Housing Sector backlog by upgrading substandard homes. The Despite strong ambitions, the sector’s near-term GHG program renovates approximately 200,000 housing mitigation potential is modest. As low-income homes units annually, improving safety, durability, and already consume minimal energy, primarily for lighting living conditions for low-income households. The and basic appliances, this limits the overall impact of houses built under the BSPS program are simple, non- emissions reduction. A 2022 simulation in support of the engineered homes. World Bank's Indonesia Country Climate and Development • Rusunawa (Public Rental Housing): This vertical rental Report (CCDR) revealed that retrofitting 486,400 low- housing program supports low-income groups and income homes would reduce emissions by approximately resettled populations, particularly those earning below 4 million metric tons of CO2 over 30 years. In contrast, the provincial minimum wage (UMP). Rent is capped upgrading 144,400 air-conditioned commercial homes at 30% of UMP or less. The program delivers about could achieve a reduction of 10 million metric tons of CO2 8,000 units per year, with 28,722 units completed in the same period – more than double the impact with to date. 31 World Bank, “Implementation Completion and Results Report - National Affordable Housing Program.” 32 World Bank provides support on the IGAHP conceptual technical development. Asia Development Bank has indicated its intention to support the financing of Phase I of the IGAHP. 33 World Bank, Indonesia: Country Climate and Development Report. 20 less than a third of the units.33 This finding underscores appliances and a greater reliance on public transit, using the importance of targeting high-energy-use buildings in electricity mainly for lighting (10%), basic appliances climate mitigation strategies. (61%), and cooling (29%).34 While this limits their Current green building regulations exclude most affordable mitigation potential, their exposure to climate risks is high, housing. The Government’s green building certification as homes are often located in floodplains, polluted zones, system introduced in 2021, BGH, only mandated to or urban heat islands. Therefore, green housing strategies buildings over four stories or 50,000 m². This threshold must prioritize adaptation through resilient design, passive effectively excludes most low-income housing projects. As a cooling, and safer site planning, while recognizing the result, and without targeted incentives, the uptake of green limited emissions these households generate. standards in the affordable housing sector remains low. Climate adaptation emphasizes designing for resilience The green dimension is intended for implementation against extreme events. Resilient buildings are constructed through the IGAHP framework. This IGAHP framework to withstand heatwaves, flooding, earthquakes, and plans to prepare Government-led housing developments to rising sea levels. Techniques include elevated foundations adopt BGH certification, laying the foundation for broader for flood protection, reinforced materials for seismic green compliance in the low-income housing sector. resistance, and insulated roofs or natural ventilation for passive cooling. Evidence from the U.S. shows that every A unified, context-specific definition of “green” for $1 invested in resilient construction saves at least $4 in affordable housing is urgently needed. The three primary future recovery costs, demonstrating the dual economic certification systems – BGH, IFC’s EDGE, and GBCI’s and environmental benefits of integrating resilience into the Greenship – each address a broad range of sustainability built environment.35 criteria but differ in their distinctive elements: EDGE focuses on embodied carbon and its calculation, BGH While earthquakes are not climate-induced hazards, includes resilience standards, and Greenship considers their inclusion in adaptation strategies is essential in the location efficiency. While all emphasize resource efficiency, Indonesian context. Although climate adaptation typically none were specifically designed to address the unique needs refers to resilience against hydrometeorological hazards and constraints of low-income housing. Harmonizing like floods, heatwaves, and sea-level rise, in Indonesia, existing green certification systems and developing tailored earthquakes represent one of the most deadly and recurrent guidance for the affordable housing segment are critical to threats—particularly for low-income households. These scaling green solutions for the populations most vulnerable communities often reside in self-built homes constructed to climate change risks. without adherence to seismic standards or structural oversight, making them highly vulnerable to collapse during even moderate earthquakes. Therefore, any 1.2.2 A Dual Focus on Climate Adaptation discussion of adaptation in affordable housing must adopt and Mitigation a broader interpretation that encompasses both climate Distinguishing between climate adaptation and mitigation and seismic risks. In this context, resilient housing means is essential for effective green housing policy, particularly in not only withstanding the impacts of a changing climate, the affordable segment. Low-income households contribute but also surviving disaster-related events through improved little to emissions due to limited access to energy-intensive construction quality, safer materials, and standardized structural design. 34 GBPN Study, 2024 35 National Institute of Building Science, “Natural Hazard Mitigation Saves 2019 Report.” RESILIENT FOUNDATIONS, GREEN FUTURES 21 Climate mitigation focuses on reducing emissions and Resilient construction that meets minimum structural environmental impact through design. Green building integrity standards must be prioritized as a prerequisite mitigation strategies aim to lower energy, water, and to integrating green features. Chronic heat exposure and embodied carbon use. Passive design approaches harness acute hazards like floods and earthquakes pose immediate natural ventilation, shading, and daylight to reduce threats to health and housing stability. Resilience-focused dependence on mechanical systems. Active strategies solutions, such as thermal comfort improvements and include efficient Heating, Ventilation, and Air Conditioning structural reinforcement, should be prioritized, especially (HVAC), smart lighting, and renewable energy technologies in areas where risks are rising due to climate change. At the such as rooftop solar panels. Together, these reduce same time, these solutions should progressively incorporate greenhouse gas emissions and promote sustainability. climate mitigation features to reduce long-term emissions and promote sustainability. Resilient construction that meets minimum structural integrity standards must be prioritized as a prerequisite This roadmap prioritizes resilient construction while to integrating green features. Chronic heat exposure and paving the way for low-carbon housing transformation. acute hazards like floods and earthquakes pose immediate Green solutions for low-income housing should begin with threats to health and housing stability. Resilience-focused disaster risk reduction and gradually integrate emission- solutions, such as thermal comfort improvements and reducing technologies and climate financing. The following structural reinforcement, should be prioritized, especially sections present practical strategies for both adaptation in areas where risks are rising due to climate change. At the and mitigation, including passive design, disaster- same time, these solutions should progressively incorporate resistant construction, risk-informed and sustainable site climate mitigation features to reduce long-term emissions neighborhood planning, renewable energy integration, and promote sustainability. and resource-efficient prototypes. Supporting systems for certification, financing, and institutional reform are also explored to enable large-scale implementation. 22 CLIMATE ADAPTATION Embed resilience to climate shocks, including flooding, Objective : earthquakes, and heat stress, into housing design, construction, and policy to safeguard lives, assets, and public investments. Action A : Passive Cooling for Thermal Stress Action B : Resilient Housing for Floods & Earthquakes Action C : Risk-Informed Settlement Planning CLIMATE MITIGATION Objective : Build low-carbon, durable, and energy-efficient housing to reduce emissions while gradually shifting toward renewable energy sources. Action D : Reduce Operational & Material Emissions Action E : Rooftop Solar PV Integration Action F : Neighborhood-Scale Sustainability CROSS-CUTTING ACTIONS Objective : Establish enabling systems through regulation, quality assurance, certification, and financing to support the scalable, verifiable, and sustained delivery of green and resilient housing. Action G : Quality Assurance and Quality Control, Permitting, and Certification Process Action H : Green Financing FIGURE 2. DIFFERENCES BET WEEN CLIMATE ADAPTATION, CLIMATE MITIGATION, AND CROSS-CUTTING ACTIONS RESILIENT FOUNDATIONS, GREEN FUTURES 23 02 Climate Adaptation & Disaster Resilience Action Framework Climate adaptation and disaster resilience prepare communities to withstand and recover from unavoidable climate-related hazards such as floods, heatwaves, and earthquakes to safeguard lives, livelihoods, and assets. 24 2.1 ACTION A: COMBATING EXTREME HEAT WITH PASSIVE COOLING DESIGN SOLUTIONS As extreme heat becomes a growing threat, integrating passive cooling design measures into low-income housing is essential to protect health, improve livability, and reduce reliance on energy- intensive air conditioning. KEY RECOMMENDATIONS: 1. Scale up passive cooling design in low-income homes to safeguard families from extreme heat. 2. Integrate passive cooling design across Government housing programs to protect families and reduce energy demand. 3. Promote passive cooling design through local governments, NGOs, and communities to keep low-income households safe from extreme heat. 2.1.1 Intervention Rationale Indonesia faces rising risk from the compounding impact Families living in simple non-engineered housing experience of heat and climate pressures. With maximum daily only six hours per day within the comfortable temperature temperatures that hover around 30–33°C and an average threshold of 27°C. Poor design and low-quality materials— humidity level of 70% to 90%, Indonesia is in the extreme both in the homes and surrounding neighborhoods—make caution to extreme danger zone of heat index36 (Figure 3). the buildings thermally inefficient and leave them exposed The precipitation level in Indonesia often exceeding 300 mm to high solar heat without enough protection. Women and in many regions further contributing to persistently high children, who are more likely to remain at home during humidity . The World Health Organization notes that high 37 the day, face an even greater risk, as temperatures begin to temperature and humidity together create environmental rise as early as 8:30 a.m. Alarmingly, indoor temperatures heat stress, which can rapidly lead to acute health risks are higher than outdoor temperatures between 3 p.m. and and exacerbate chronic conditions. This index also aligns 6 a.m., when most occupants are at home. This prolonged with ASHRAE Standard 5538, showing that dry bulb exposure to heat underscores the urgent need for effective temperatures consistently fall outside the adaptive thermal cooling solutions for low-income families living in simple comfort range throughout the year39. non-engineered houses. 36 Thermal Resilience by Design: Passive Cooling Solutions for Low-Income Housing in Indonesia, 2025 37 Badan Meteorologi Klimatologi Geofisika, “I-TMY | Informasi Iklim BMKG.” 38 ASHRAE Standard 55, formally known as "Thermal Environmental Conditions for Human Occupancy," is a standard that provides guidelines for acceptable indoor thermal conditions to ensure thermal comfort for building occupants. https://www.ashrae.org/technical-resources/bookstore/standard-55-thermal-environmental- conditions-for-human-occupancy RESILIENT FOUNDATIONS, GREEN FUTURES 25 Low-income families are especially vulnerable to heat With limited access to cooling appliances, low-income stress, particularly in urban areas where poor neighborhood households need more affordable solutions to keep their design and lack of shading worsen exposure. 40 Prolonged families safe. In Indonesia, the cost of air conditioning (AC) heat exposure can lead to serious health issues such as can approach the total monthly income of households in dehydration, heat stroke, respiratory and cardiovascular the lowest 20% income bracket, rendering it largely complications, and an increased risk of waterborne diseases. unaffordable for the most vulnerable.42 As a result, many Evidence from other countries indicates that heat exposure households opt for secondhand AC units as a cheaper also affects learning outcomes and has been linked to rising alternative, but their poor performance often leads to high rates of domestic violence, especially against women. 41 energy use, elevated utility costs, and greater greenhouse Limited income and lack of social protection restrict access gas emissions.43 This underscores the urgent need for to healthcare, making it harder for vulnerable groups simple, energy-efficient, and affordable cooling solutions to cope. tailored to low-income households. NOAA national weather service: heat index Range of Temperature in Indonesia TEMP. 27ºC 28ºC 29ºC 30ºC 31ºC 32ºC 33ºC 34ºC 36ºC 37ºC 38ºC 39ºC 40ºC 41ºC 42ºC 43ºC RELATIVE HUMIDITY 40% 27ºC 27ºC 28ºC 29ºC 31ºC 33ºC 34ºC 36ºC 38ºC 41ºC 43ºC 46ºC 48ºC 51ºC 54ºC 58ºC 45% 27ºC 28ºC 29ºC 31ºC 32ºC 34ºC 36ºC 38ºC 40ºC 43ºC 46ºC 48ºC 51ºC 54ºC 58ºC 50% 27ºC 28ºC 29ºC 31ºC 33ºC 35ºC 37ºC 39ºC 42ºC 45ºC 48ºC 51ºC 55ºC 58ºC 55% 27ºC 29ºC 30ºC 32ºC 34ºC 36ºC 38ºC 41ºC 44ºC 47ºC 51ºC 54ºC 58ºC 60% 28ºC 29ºC 31ºC 33ºC 35ºC 38ºC 41ºC 43ºC 47ºC 51ºC 54ºC 58ºC Range of Relative Humidity in Indonesia 65% 28ºC 29ºC 32ºC 34ºC 37ºC 39ºC 42ºC 46ºC 49ºC 53ºC 58ºC 70% 28ºC 30ºC 32ºC 35ºC 38ºC 41ºC 44ºC 48ºC 52ºC 57ºC 75% 29ºC 31ºC 33ºC 36ºC 39ºC 43ºC 47ºC 51ºC 56ºC 80% 29ºC 32ºC 34ºC 38ºC 41ºC 45ºC 49ºC 54ºC 85% 29ºC 32ºC 36ºC 39ºC 43ºC 47ºC 52ºC 57ºC Caution 90% 30ºC 33ºC 37ºC 41ºC 45ºC 50ºC 55ºC Extreme Caution 95% 30ºC 34ºC 38ºC 42ºC 47ºC 53ºC Danger 100% 31ºC 35ºC 39ºC 44ºC 49ºC 56ºC Extreme Danger FIGURE 3. INDONESIA HEAT INDEX (ORIGINAL CHART DEVELOPED BY STEADMAN, 1979) 39 Specifically in Gresik Area (Juanda Meteorological Station), where the thermal survey was conducted 40 UN– Habitat, “World Cities Report 2024.” 41 Simister and Cooper, “ Thermal Stress in the U.S.A: Effects on Violence and on Employee Behaviour.” 42 World Bank Task Team analysis based on Household Income Level and Market Price of AC units in Indonesia. 43 Never, “Green and Social Regulation of Second Hand Appliance Markets: The Case of Air Conditioners in the Philippines.” 26 34 600 Highest Tout 33 Ti max - Ti min = 10.6˚C 500 T Indoor & T Outdoor (°C) 32 To max - To min = 12.4˚C Highest Tin Solar Radiation (W/m²) 31 T at 11:30 -14:30 = 0.86˚C 400 30 29 300 28 27 200 26 100 25 24 0 0.00 1.00 2.00 3.00 4.00 5.00 6.00 7.00 8.00 9.00 10.00 11.00 12.00 13.00 14.00 15.00 16.00 17.00 18.00 19.00 20.00 21.00 22.00 23.00 0.00 Hour Average of T Indoor (°C) Average of T out (°C) Solar Radiation Comfort FIGURE 4. THE BASELINE INDOOR TEMPERATURE OF SIMPLE NON-ENGINEERED HOUSE 2.1.2 Intervention Approach and (E) Ceiling with gable ventilation44. Please refer to the study methodology under Annex 1. The improvement Passive cooling design is essential for protecting low- in thermal performance across all models tested in this income households from rising heat. As heat exposure study demonstrates a significant potential to reduce heat intensifies, integrating passive cooling design is stress in the context of Indonesia’s climate. Kjellstrom increasingly vital to protect family health and sustain et al. (2016) found that reducing indoor temperatures economic and educational productivity. Unlike energy- by just 1-2°C in tropical climates can decrease the Wet intensive active cooling systems, passive cooling uses Bulb Globe Temperature (WBGT) enough to reduce heat building design and materials to regulate temperature stress risk classification from "high" to "moderate" for naturally, offering a more sustainable and cost-effective many workers45. solution over time. Although upfront costs may be slightly higher, passive cooling strategies typically offer lower Among the tested designs, aluminum foil roof insulation maintenance requirements, longer lifespans, and greater proved to be the most effective in reducing peak affordability over their lifecycle. To ensure widespread temperatures, stabilizing indoor temperature, and adoption in self-built, low-income housing, however, these improving comfort. This intervention reduces heat transfer solutions must remain simple and cost-effective. through multiple mechanisms. Its technical benefits, such as high reflectivity47, extremely low emissivity48 and Field-tested simple passive cooling measures show a effective moisture control, combined with its moderate reduction range of 0.82 to 1.63 °C on average compared cost (6% of total construction expenses), make it a strong to homes without interventions. A study conducted by the candidate for large-scale adoption. Homeowners also World Bank, in collaboration with Habitat for Humanity report strong satisfaction with the results, mentioning that tested four passive cooling designs in simple non- their house feels cooler on scorching hot days and warmer engineered housing, consisting of: (B) Reflective roof paint, on rainy days. (C) Cross-ventilation, (D) Aluminum foil roof insulation, RESILIENT FOUNDATIONS, GREEN FUTURES 27 Roof tiles are painted with reflective roof paints Strategically placing windows for cross-ventilation effect Model B – Reflective Roof Paint Model C – Cross Ventilation A narrow slit in the ceiling allows hot air to rise in to the attic Aluminum foil installed between wooden Hot air is trapped in truss and roof tiles the attic and released through gable ventilation Model D – Aluminum Foil Roof Insulation Model C – Cross Ventilation FIGURE 5. ILLUSTRATION OF INTERVENTION MODELS (MODEL A IS A TYPICAL HOUSE WITHOUT INTERVENTIONS AS BASELINE CONTROL) 44 Selection of interventions was based on their added design value to the baseline model (which already includes shading elements such as roof overhang), as well as considerations of cultural relevance, applicability, and cost-efficiency. 45 Kjellstrom and and Lemke, “Workplace Heat Stress, Health and Productivity – an Increasing Challenge for Low and Middle-Income Countries during Climate Change.” 46 Δ(ΔT) is a normalized metric developed for comparison purpose, further explanation in Annex 1 47 Aluminum foil reflects most of the solar waves (reflectivity: 0.95) 48 Extremely low emissivity, meaning it does not release much of the absorbed heat back into the indoor space (0.03–0.05) 28 ( T) Intervention - Baseline Model (C) 3 2 1,63 1 0,86 0,82 0 -0,55 -1 -2 ( T) Model B ( T) Model C ( T) Model D ( T) Model E Box Plot Mean FIGURE 6. IBOXPLOT SHOWING THE REDUCTION IN INDOOR TEMPERATURE COMPARED TO THE BASELINE MODEL A 46 Ceilings with gable ventilation also demonstrated to foil insulation, reflective paint is generally less effective significant thermal improvements. This solution creates a at limiting heat transfer into the home. Its performance thermal buffer by separating the living space from hot air also varies depending on roof materials and local climate accumulating in the roof and allows warm air to escape. conditions.50 Still, both are easy to apply and should be part The combined features of a thermal buffer zone and of the passive cooling design toolkit, particularly in areas ventilation explain why this model performs well across with consistent wind or for house built with low emissivity multiple comfort measures, including temperature stability, roofing materials, such as metal roof. humidity control, and delayed heat buildup indoors. While Optimal results are achieved through interventions its performance is slightly less stable than foil insulation that address multiple heat-transfer mechanisms51, as due to varying external conditions, it remains effective demonstrated by aluminum-foil insulation and gable- and culturally aligned with common building practices. ventilated ceilings. Aluminum foil blocks solar radiation However, it potentially requires greater upfront investment and delays heat flow, while gable-ventilated ceilings add depending on the ceiling material.49 thermal buffering and improve airflow. These material- Cross ventilation and reflective roof paint, while technically based solutions consistently outperform space-modification less impactful, remain valuable and contextually strategies, such as ventilation, that relies on occupant appropriate solutions for Indonesia’s tropical climate. behavior. This benefit is reflected in Figure 9, which presents Cross ventilation improves airflow and helps expel humid, a weighted composite score evaluating each solution’s stagnant indoor air, enhancing comfort in high-moisture effectiveness across four equally weighted performance environments. Reflective roof paint increases a surface’s indicators: peak heat control, temperature stability, peak albedo – its ability to reflect sunlight rather than absorb humidity control, and humidity stability. it – which can help reduce heat gain. However, compared 49 Thermal Resilience by Design: Passive Cooling Solutions for Low-Income Housing in Indonesia, 2025 50 Thermal Resilience by Design: Passive Cooling Solutions for Low-Income Housing in Indonesia, 2025 51 Thermal Resilience by Design: Passive Cooling Solutions for Low-Income Housing in Indonesia, 2025 RESILIENT FOUNDATIONS, GREEN FUTURES 29 Passive cooling yields modest climate mitigation but on the power grid, curbs excessive energy demand, and high adaptation value. While emissions savings are low, ensures safer living conditions during extreme events when equivalent to about 0.1 tCO2 per unit annually, passive electricity may be disrupted. design is a cost-effective way to enhance comfort and safety Scaling passive cooling solutions require strong community overall. Embedding these features within the BSPS home engagement and capacity building. improvement program can drive large-scale adoption of In self-built housing, construction practices are shaped by climate-resilient housing solutions. The program’s existing cultural norms and daily habits, which can unintentionally facilitation and monitoring mechanisms can help guide the block ventilation or compromise cooling performance. effective implementation of these strategies. Outreach is essential to help homeowners understand Passive cooling offers lasting benefits, even in homes the benefits of passive cooling and how to preserve it with mechanical cooling like fans or air conditioners, over time. For instance, many BSPS homes lack built- by reducing energy use and lowering electricity costs. in kitchens, prompting households to build extensions Integrating passive design is vital for promoting energy- that reduce airflow. Awareness and design guidance must efficient and sustainable housing. As the most cost-effective accompany construction. and climate-resilient solution, passive cooling eases pressure Ti max - Ti min = 6,3ºC Ti max - Ti min = 7,9ºC Ti max - Ti min = 10,7ºC Ti max - Ti min = 12ºC ΔT at 11:30-14:30 = 2,35ºC ΔT at 11:30-14:30 = 1,15ºC 34 34 33 33 32 T Indoor &T Outdoor (%) 32 T Indoor &T Outdoor (%) 31 31 30 30 29 29 28 28 27 27 26 26 25 25 24 24 00.00 01.00 02.00 03.00 04.00 05.00 06.00 07.00 08.00 09.00 10.00 11.00 12.00 13.00 14.00 15.00 16.00 17.00 18.00 19.00 20.00 21.00 22.00 23.00 00.00 01.00 02.00 03.00 04.00 05.00 06.00 07.00 08.00 09.00 10.00 11.00 12.00 13.00 14.00 15.00 16.00 17.00 18.00 19.00 20.00 21.00 22.00 23.00 Hour Hour T Indoor T Outdoor Comfort T Indoor T Outdoor Comfort FIGURE 7. GRAPH SHOWING THE TEMPERATURE OF HOUSES WITH ALUMINUM FIGURE 8. GRAPH SHOWING THE TEMPERATURE OF HOUSES WITH FOIL ROOF INSUL ATION. CEILING AND GABLE VENTILATION. THIS MEASURE REDUCES THE PEAK INDOOR TEMPERATURE. 30 Technical Performance Score Incremental Cost 3,5 3.5 million 3,0 3 million 2,5 2.5 million 2,0 Humidity Stability 1,5 Humidity Performance 2 million 1,0 Temperature Stability 1.5 million Heat Performance 0,5 Total Cost 0,0 1 million D: Aluminum Foil E: Ceiling with B: Re ective C: Cross-ventilation Roof Insulation Gable Ventilation Roof Paint FIGURE 9. GRAPH SHOWING THE COMPOSITE TECHNICAL PERFORMANCE SCORE AND INCREMENTAL CONSTRUCTION COST Local governments, NGOs, and community centers play Finally, further research is needed to develop integrated and a vital role in advancing and scaling context-appropriate scalable cooling prototypes. The combined application of housing solutions. The Government can pilot passive multiple passive design strategies, particularly in alternative cooling designs through existing programs, engaging Self- housing typologies such as row-houses, which are common Construction Centers (Klinik Rumah Swadaya), local in KPR Subsidi developments, should be evaluated across governments, and NGOs. Workshops and community Indonesia’s diverse climatic zones to assess their overall feedback should be embedded into CSR-based housing impact on thermal comfort and livability. These insights can projects and public housing programs to ensure solutions are inform the development of standardized, climate-resilient context-appropriate and locally accepted. The figure below housing prototypes suitable for low-income communities outlines a four-step roadmap for scaling passive thermal across Indonesia. comfort strategies, culminating in their integration into the minimum construction standards for subsidized housing. Adopt passive Implement Thermal Adopt thermal Adoption in the low-cost design comfort passive comfort metrics in minimum construction strategies in pilot strategies in green certification standard for criteria subsidized housing projects government-led programs FIGURE 10. PROPOSED ROADMAP FOR ADOPTING GREEN PASSIVE COOLING SOLUTIONS ADDRESSING THERMAL STRESS RESILIENT FOUNDATIONS, GREEN FUTURES 31 2.2 ACTION B: PROMOTE RESILIENT HOUSING DESIGN AND CONSTRUCTION TO WITHSTAND FLOODS AND EARTHQUAKES Strengthening housing structures against seismic and flood risks is critical to saving lives and minimizing damage to housing assets, especially in Indonesia’s most hazard-prone regions. KEY RECOMMENDATIONS: 1. Scale up use of earthquake-resilient housing prototypes in Government programs. 2. Develop and integrate retrofit guidelines for seismic safety in existing homes. 3. Plan for occupant-led modifications to ensure structural and climate resilience. 4. Invest in flood-resilient housing research and standards to guide safer construction. 2.2.1 Intervention Rationale the presence of regulatory frameworks.54 Simple non- engineered housing is especially vulnerable, with collapse Indonesia faces diverse and severe disaster risks, with floods risks heightened by untrained construction labor and weak and earthquakes leading in frequency and impact. Between quality control. 2020 and 2024, Indonesia experienced a high number of natural disasters. Floods were the most frequent, with 6,913 Prototype designs for earthquake-resilient housing exist events causing 967 deaths , while earthquakes, though less 52 but lack implementation monitoring. Ministerial Decree common with 113 occurrences, resulted in 755 fatalities 2947/2024 offers standard structural designs (22 m²–36 due to their higher severity. 53 This contrast underscores m²) based on national building codes. These designs are the need for hazard-specific strategies: while floods cause integrated into the Sistem Informasi Manajemen Bangunan widespread but lower-intensity impacts, earthquakes are Gedung55 (SIMBG) construction permitting system, but acutely deadly and devastating per event. data on actual uptake and construction quality remains limited, making it difficult to assess their real-world impact. Earthquakes pose a significant threat due to poor housing quality. Although Indonesia has adopted earthquake- Floods, while less deadly per event, cause widespread and resistant standards (SNI 1726:2019), the majority of homes chronic damage. In the last five years, over four million are self-built and often lack critical structural elements such homes have been inundated and 25,000 severely damaged as properly designed columns, beams, and trusses, leaving by flooding. Unlike earthquake resilience, flood-resilient them highly vulnerable to seismic damage. Quality issues housing in Indonesia lacks dedicated standards, and continue to affect even government-led housing projects, available retrofitting techniques remain limited. Urban with problems such as substandard rebar, improperly flood management efforts tend to prioritize infrastructure mixed concrete, and nonstandard bricks persisting despite solutions over housing-level adaptations, an approach that 52 Badan Nasional Penanggulangan Bencana, “Data Informasi Bencana Indonesia.” 53 Badan Nasional Penanggulangan Bencana, “Data Informasi Bencana Indonesia.” 54 Pribadi and Kusumastuti, “Learning from Recent Indonesian Earthquakes: An Overview to Improve Structural Performance.” 55 SIMBG is Indonesia’s online platform for managing the issuance of building permits (PBG – Persetujuan Bangunan Gedung) and certificates of proper function (SLF – Sertifikat Laik Fungsi), streamlining the previously manual and often fragmented permitting process. 32 is increasingly insufficient as low-income and informal well adapted to flood events as buildings were elevated communities expand in flood-prone areas. As an example, on stilts in rural and coastal areas. This practice is a government subsidized home-ownership program in gradually faded as market preferences shift towards Bekasi was submerged in flood water, see Figure 11. brick masonry houses. Relocation is rarely feasible for low-income households, These grassroots adaptation measures reflect both resilience making in-situ adaptation essential. In cities like Jakarta, and resource constraints. They demonstrate the ingenuity 20 to 25% of residents live in kampungs, and 4 to 5% of low-income communities while highlighting the urgent squat on riverbanks or floodplains. 57 Studies show that need for formal, scalable solutions. severely affected households are 75% less likely to relocate58. Consequently, many communities responded to flooding risks by adopting locally driven adaptation measures such as: • In Muara Angke, residents raise ground levels using clamshell waste, creating porous surfaces that dissipate water59, as per Figure 12 below. • Stilt houses allow water to pass underneath, with the FIGURE 12 STILT HOUSE AND CL AMSHELL WASTE AS POROUS SURFACE IN KAMPUNG KERANG IJO (PRANA ET AL., 2024) space used for duck farming. • In Muara Baru, residents wet-proof homes by Investing in flood-resilient housing standards, research, and elevating valuables and organizing furniture to reduce support for local adaptations is critical to safeguard lives flood damage . 60 and livelihoods in increasingly climate-vulnerable areas. • Families with multi-story homes often shelter neighbors on upper floors during flooding events. 2.2.2 Intervention Approach • Indonesian traditional and vernacular architecture was 1. Scale Up the Use of Earthquake-Resilient Building Prototypes in Government Housing Program To enhance structural safety in low-income housing, the Government must accelerate the adoption of standardized earthquake-resilientx prototypes within the permitting process (PBG and SLF). Prototype designs for 22 m², 30 m2, 32 m², and 36 m² units, developed under Kepmen 2947/2024 and integrated into SIMBG, offer SNI- compliant, cost-effective solutions for households without access to licensed engineers. Yet uptake remains limited due to weak monitoring and lack of awareness. Public FIGURE 11. KPR SUBSIDI HOUSING COMPLEX IN BEKASI SUBMERGED IN FLOOD outreach, training for local authorities, and integration into WATERS (MARCH 2025) 56 56 inewsid, “Pengembang Buka Suara Soal Banjir Setinggi Atap di Perumahan The Arthera Hill 2 Bekasi.” 57 UN-Habitat, The Challenge of Slums. 58 Langlois et al., “Household Flood Severity and Migration Extent in Central Java.” 59 Prana et al., “Informal Adaptation to Flooding in North Jakarta, Indonesia.” 60 Simarmata, Phenomenology in Adaptation Planning. RESILIENT FOUNDATIONS, GREEN FUTURES 33 community facilitation mechanisms (e.g., BSPS) are needed to boost implementation. Material quality and construction skills are critical enablers of structural safety and resilience. Confined masonry structures depend on the proper use of steel reinforcement and quality bricks to ensure seismic resilience. While regulations still permit plain rebars (besi polos), SNI 2847:2019 recommends using deformed rebars (besi ulir) for enhanced earthquake performance, particularly in high-risk zones, where their use should be mandatory. Brick quality remains uneven due to informal production methods, yet alternatives like Autoclave Aerated Concrete (AAC) or Cellular Lightweight Concrete (CLC) (locally FIGURE 13. EXAMPLE OF RETROFIT GUIDELINE AND COMMON known as hebel) offer more consistent performance. CONSTRUCTION MISTAKES DEVELOPED BY BUILD CHANGE, WORLD BANK, AND MOHS FOR THE IGAHP PILOT 62 Strengthening enforcement of material standards and removing substandard products from the market are critical steps. At the same time, widespread gaps in construction and CBOs by leveraging simple diagnostic tools. Under the skills persist61, with most masons lacking formal training, IGAHP project led by MoHS and supported by the World highlighting the urgent need for a national certification Bank, a resilient retrofit model has been developed and is program focused on earthquake-resistant construction. being piloted, whose lessons should inform future national scale-up efforts. 2. Institutionalize Earthquake Retrofit Guidelines for Existing Housing Ferrocement offers a low-cost retrofit option for substandard Given the widespread vulnerability of self-built and homes. Ferrocement strengthens masonry walls by adding developer-led homes, retrofitting must become a national reinforced mesh to both sides without requiring demolition, strategy. High fatality rates are directly linked to poorly offering an affordable, easy-to-apply, and non-invasive constructed housing that lacks structural elements like solution well-suited to low-income households. Even partial columns, beams, or trusses. While BSPS and NAHP have application in bedrooms, the most vulnerable spaces during highlighted these risks, no retrofit standard currently exists nighttime earthquakes, can significantly reduce fatalities63. for improving the seismic safety of the existing housing This solution is especially promising to scale community- stock. based retrofitting efforts. The Ministry of Public Works (MPW) and Ministry of 3. Anticipate and Guide Incremental Construction Housing and Settlement (MoHS) should develop national Over 90% of beneficiaries in the Government KPR Subsidi retrofit guidelines based on SNI codes and integrate them into programs make structural changes, often adding rooms BSPS and other housing upgrade programs. Pilot retrofits or extra floors, within two years63. These unplanned should be launched in high-risk areas for confined masonry modifications introduce unaccounted loads and jeopardize and timber-frame homes, supported by local governments structural integrity, especially in seismic zones. 61 Pribadi et al., “Promoting Humanitarian Engineering Approaches for Earthquake-Resilient Housing in Indonesia.” 62 The IGAHP Pilot is a collaborative effort between the World Bank, MoHS, Build Change, and SMF to test credit-linked subsidy/ incentive scheme for green and resilient self-construction, retrofit, and developer-built houses. The pilot incorporates green and resilient construction and retrofit guidelines, as well as a comprehensive QAQC mechanism to ensure quality. 63 Ismail, Boen, and Thamrin, “Gradual Strengthening Of Existing Masonry Houses With Ferrocement Bandaging In Indonesia For Educating The Common People To Be Self-Reliant And Self-Supporting.” 34 To mitigate risks, programs must provide guidance for BOX 1. Cambodia social housing design for safe incremental expansion. Modular housing designs incremental growth65 that allow phased horizontal or vertical expansion can help prevent unsafe additions due to households lacking technical knowledge. Construction permits or Persetujuan Bangunan Gedung (PBG) and certificates of proper function Sertifikat Laik Fungsi (SLF) issuance should include clear visual or written guidance on structural dos and don’ts. Local housing officials and facilitators must be trained to advise residents on how to expand safely within design limits. 4. Establish a National Standard for Flood- Resilient Housing Despite being Indonesia’s most frequent disaster, floods lack a formal housing design standard. Over 4 million homes have been flooded and 25,000 seriously damaged in the past five years. Current adaptation practices in informal settlements, such as raising floors with clamshell waste or building stilt homes, are practical solutions but largely informal, undocumented, and inconsistent in their application. A national flood-resilient housing standard is urgently Habitat for Humanity Cambodia, with local needed. The Government should invest in applied research partners, developed an incremental housing model to document, test, and formalize housing adaptation that allows families to expand vertically over time. techniques. Pilot demonstrations in frequently flooded The initial construction includes only the ground areas (e.g., coastal and riverine settlements) can support floor and core structure, costing around USD 3,500, the development of modular, low-cost design options. and is designed to support a future second story. These standards should eventually be embedded in Families can upgrade their homes gradually as building codes, urban planning frameworks, and housing finances allow, spending an incremental USD 2,100 subsidy programs. to complete interiors and add a second floor. Leverage community-led innovations through participatory planning. Rather than replace grassroots solutions, the Government should leverage them through co-production, engaging communities, local builders, and NGOs in the design process. Technical agencies can offer risk assessments and structural support, while communities contribute local knowledge and maintenance strategies. This ensures designs are both effective and socially accepted. 64 Source: Survey by GBPN, 2024 65 Source: Habitat for Humanity Cambodia RESILIENT FOUNDATIONS, GREEN FUTURES 35 BOX 2. Building-Level Flood Adaptation Strategies Bioswales / raingarden Safe haven (core living function on second floor) Elevated stilts construction Raised electrical sockets Dikes & walkway Wet-proofed basement Drainage pipe Vegetated embankment FIGURE 14 BUILDING LEVEL ADAPTATION 66 Flood adaptation at the building level involves three • Dry-proofing aims to keep water out using sealed main strategies: wet-proofing, dry-proofing, and flood openings, waterproof coatings, reinforced structures, avoidance67. Each strategy uses architectural, structural, and flood-resistant MEP installations. and MEP (mechanical, electrical, plumbing) techniques • Flood avoidance raises buildings above flood levels to reduce damage and boost resilience. using stilts or elevated plinths, relocating key • Wet-proofing allows water to enter but infrastructure to upper floors, and ensuring structures minimizes damage and speeds recovery through can withstand both vertical and lateral forces. water-resistant materials, elevated systems, and easy-to-replace components. 66 Adapted from Baca Architecture, “World Flood Handbook | BACA Architects.” 67 Jha, Bloch, and Lamond, Cities and Flooding . 36 2.3 ACTION C: RISK-INFORMED SITE PLANNING AND URBAN DESIGN STRATEGIES IN INTEGRATED HOUSING AND SETTLEMENT UPGRADING PROJECT Planning and upgrading housing settlements with embedded disaster risk data ensures safer communities and more effective emergency responses. KEY RECOMMENDATIONS: 1. Incorporate disaster risk-responsive site planning into housing and settlement design. 2. Apply neighborhood-scale design solutions to reduce earthquake, flood, and heat risks. 3. Combine physical interventions with community engagement and public awareness efforts. 2.3.1 Intervention Rationale construction quality through the implementation of QAQC systems and the use of wire-mesh technology to strengthen Climate adaptation must move beyond the scale of earthquake resilience. By 2023, BSPS had delivered home individual buildings and be integrated into broader improvement assistance to over 980,000 beneficiaries68. neighborhood- and city-level disaster risk reduction Meanwhile, the KOTAKU program, implemented by the frameworks. Individual housing units do not exist in Ministry of Public Works and Housing (MPWH) and isolation, rather, they are embedded within wider urban co-financed by the World Bank, Asian Infrastructure ecosystems. Therefore, resilience must be addressed Investment Bank (AIIB), and Islamic Development Bank collectively through coordinated, multi-level planning that (IsDB) under the National Slum Upgrading Project spans households, neighborhoods, and cities. (NSUP), focuses on slum upgrading through infrastructure This integrated approach is particularly relevant for investments and community empowerment. To date, Indonesia’s long-standing housing improvement and slum KOTAKU has improved living conditions for 8.7 million upgrading programs for low-income neighborhoods, people, including 4.4 million women69. namely BSPS and National Slum Upgrading Program (or Although both programs have previously contributed KOTAKU). These programs have laid a foundation for to disaster management, their potential role in climate improving physical infrastructure and housing resilience, disaster adaptation can be vital. NAHP’s support to BSPS and they must now evolve to incorporate climate was instrumental in enhancing the structural integrity and adaptation. The BSPS program, backed by $312 million earthquake resilience of housing through QAQC systems in World Bank financing through the NAHP, provides in- and new construction technologies. Similarly, NSUP kind subsidies—such as construction materials and labor extended its mandate to support post-disaster recovery in support—to households in the bottom 40% income group, Palu, Donggala, and Sigi following the 2018 earthquake with particular attention to female-headed households, and tsunami, which caused over 4,000 deaths, displaced the elderly, and people with disabilities. It has enhanced 170,000 people, and led to $1.3 billion in economic losses. 66 Adapted from Baca Architecture, “World Flood Handbook | BACA Architects.” 67 Jha, Bloch, and Lamond, Cities and Flooding . 68 World Bank, “Implementation Completion and Results Report - National Affordable Housing Program.” 69 World Bank, “Implementation Completion Report (ICR) Review - Indonesia National Slum Upgrading Project.” RESILIENT FOUNDATIONS, GREEN FUTURES 37 The program helped reconstruct resilient housing, water planned road networks, open space, and infrastructure can supply and sanitation systems, solid waste infrastructure, increase vulnerability. Risk-informed site planning ensures and public service buildings. that emergency access, evacuation routes, and critical Neighborhood-level adaptation strategies must be services remain functional during disasters. mainstreamed into settlement upgrading programs to Redundant road networks enhance emergency response. address the growing risks of flooding, earthquakes, and Housing developments must avoid reliance on a single thermal stress. Beyond strengthening housing structures, access road, which becomes a failure point during disaster tailored neighborhood-scale interventions such as events. Multiple access points and routes that accommodate improved drainage, heat-mitigating urban design, and emergency vehicles are essential to ensure uninterrupted community-based disaster preparedness are essential to mobility. Roads should be free from choke points that enhance climate resilience in low-income urban areas. could block evacuation or delay aid delivery. Accessible open spaces must be integrated as evacuation 2.3.2 Intervention Approaches areas. All homes should be within walking distance of clearly 1. Embed Disaster-Responsive Site Planning into marked, unobstructed open spaces that serve as emergency Housing and Settlement Design assembly points. Critical infrastructure like schools, clinics, Building resilience to disasters begins with site layout. and fire stations should be located outside high-risk zones Even when homes are built in relatively safe areas, poorly and spatially distributed to ensure uninterrupted access. FIGURE 15. LEF T – RISK-PRONE LAYOUT WITH SINGLE-ENTRY ACCESS. RIGHT – RESILIENT LAYOUT WITH MULTIPLE ENTRY POINTS ENABLING REDUNDANCY AND SAFER EVACUATION ROUTES. 38 FIGURE 16. LEF T – TRADITIONAL BAMBOO HOMES WITH FLEXIBLE JOINTS. MIDDLE – RIGID MASONRY ROW HOUSING (EXISTING). RIGHT – BUFFERED ROW HOUSES IN SUMBAWA. A layered service delivery model can improve emergency rain gardens, biopores, swales, and ponds absorb rainfall response and continuity of operations. and slow runoff. In Citarum, retention ponds reduced flood 2. Deploy Physical Design Measures to Mitigate frequency from 61% to 1.5% (2020–2023).71 Structural Earthquake, Flood, and Heat Risks defenses (e.g., embankments, river revitalization) cut flood Building typologies and neighborhood design play a central duration and area in Semarang. Mangrove restoration role in reducing disaster vulnerability. Tailored physical provides natural coastal flood protection.72 Regular interventions can significantly enhance the resilience of dredging and expansion of channels are crucial. In housing and urban infrastructure. Semarang, improved drainage reduced flood-prone areas from 522 to 466 locations.73 Pumps, dykes, and retention To enhance seismic resilience, alternative housing typologies, infrastructure increase system capacity and resilience such as light-weight flexible construction and higher-density during peak rainfall. detached housing can be considered. Indonesia’s traditional lightweight wooden houses, built with flexible, detachable Improving thermal comfort in urban areas can leverage components, perform well in earthquakes due to their shock nature-based cooling solutions and urban design strategies. absorption.70 By contrast, modern masonry row houses rely Urban greening, such as planting trees, constructing on structural rigidity, which can lead to cascading collapse parks, and expanding green corridors, can reduce local if one unit fails or if unsupervised structural modifications temperatures by up to 1.5°C and create “cool islands” up are made. Introducing small buffers between units, as to 2 km wide.74 Additionally, urban greeneries also enhance often observed in Japanese design principles, reduces force water absorption, slow water runoff, and boost natural soil transmission. Vertical townhouses (e.g., 20 m² x 2 floors) retention. High-albedo surfaces (e.g., reflective roofs, cool can offer compact yet detached alternatives from typical pavements) significantly reduce surface temperatures and row houses for high-density areas. absorb less heat. For example, permeable concrete can be up to 9°C cooler than asphalt.75 Flood Resilience can be improved by adopting multi- layered flood protection strategies. Retention systems like 70 Pribadi et al., “Promoting Humanitarian Engineering Approaches for Earthquake-Resilient Housing in Indonesia.” 71 Hamel and Tan, “Blue–Green Infrastructure for Flood and Water Quality Management in Southeast Asia.” 72 Permanasari et al., “Enhancing Urban Resilience through Integrated Flood Policy and Planning.” 73 Irawan, Syafrudin, and Budihardjo, “Evaluation of Drainage System and Flood Management in Semarang City.” 74 Santamouris et al., “Passive and Active Cooling for the Outdoor Built Environment – Analysis and Assessment of the Cooling Potential of Mitigation Technologies Using Performance Data from 220 Large Scale Projects.” 75 Ibrahim et al., “ The Impact of Road Pavement on Urban Heat Island (UHI) Phenomenon.” RESILIENT FOUNDATIONS, GREEN FUTURES 39 FIGURE 17. LEF T – FLOOD RETENTION PARK IN JAKARTA. MIDDLE – VEGETATED EMBANKMENT. RIGHT – CLEAN DRAINAGE CHANNEL IN KOTAKU. Buildings and streets can be oriented to optimize wind Disaster drills and early warning systems must be inclusive, flow and shading. Buildings oriented with shorter east and reaching even the most vulnerable groups. west facades minimizes solar gain. Well-placed windows, In conclusion, to address climate and disaster adaptation streets, and openings facilitate cross-ventilation, enhancing strategies, a range of interventions are outlined across thermal comfort without energy use.76 housing-level and neighborhood-level scales, tailored to Engage communities throughout design and implementation specific hazards including thermal stress, earthquakes, processes. Meaningful participation not only fosters a and floods. The interventions are summarized in Table 1 sense of ownership but also ensures that solutions are below that include household measures such as thermal culturally appropriate and aligned with local needs. insulation, seismic retrofitting, and wet-proofing, as well Without community engagement, even well-intentioned as settlement-scale strategies like urban greening, clustered innovations risk being rejected due to misunderstandings housing with setbacks, and drainage enhancement. or cultural disconnects. 77 Training-programs for homeowners and local builders are equally important, particularly in earthquake-prone areas, where enhancing knowledge of safe construction practices can significantly improve compliance with building standards and reduce disaster risk. Promote disaster preparedness through public awareness. Preparedness campaigns should include accessible guidance on evacuation, emergency supplies, and household safety. FIGURE 18. IN CIEUNTEUNG, PARTICIPATORY DESIGN OF A RETENTION POND CREATED RECREATIONAL BENEFITS ALONGSIDE IMPROVED FLOOD MANAGEMENT, STRENGTHENING MAINTENANCE AND COMMUNIT Y PRIDE 78 76 ASEAN Centre for Energy et al., “Passive Cooling Strategies - Current Status and Drivers of Integration into Policy and Practice within ASEAN’s Building Sector.” 77 Pribadi et al., “Promoting Humanitarian Engineering Approaches for Earthquake-Resilient Housing in Indonesia.” 78 Permanasari et al., “Enhancing Urban Resilience through Integrated Flood Policy and Planning.” 40 ADAPTATION SCALE HEAT STRESS EARTHQUAKE FLOOD Thermal insulation (e.g., Structural compliance with Wet-proofing (e.g., elevated aluminum foil, roof air gaps) building codes (e.g., SNI) electrical systems, secondary and QA/QC enforcement refuge floors) Reflective surfaces (e.g., cool Housing-level roofs, white paint) Seismic retrofitting (e.g., Dry-proofing (e.g., backflow wire-mesh reinforcement) valves, flood guards) Passive ventilation (e.g., cross ventilation, operable Lightweight, flexible Elevated floor construction windows, fans) structural systems (e.g., light (e.g., stilted homes) steel frames, gable roofs) Urban greening (e.g., street Clustered housing with safe Local water retention (e.g., trees, green corridors) for setbacks to reduce domino retention ponds, permeable microclimate regulation collapse risk paving, flood parks) Neighborhood & Heat-resilient surfacing (e.g., Community assembly points Flood defenses (e.g., Settlement-Level cool pavements, shaded and evacuation spaces bioswales, embankments, pathways) wetlands, floodgates) Seismic reinforcement Orientation-sensitive layout of critical infrastructure Drainage enhancement to optimize wind flow (e.g., water tanks, power (e.g., enlarged culverts, river substations) widening, dredging) TABLE 1. SUMMARY OF CLIMATE AND DISASTER ADAPTATION STRATEGIES BY SCALE AND HAZARD TYPE RESILIENT FOUNDATIONS, GREEN FUTURES 41 03 Climate Mitigation Action Framework Climate mitigation reduces the long-term impacts of climate change by lowering greenhouse gas emissions through energy-efficient design, sustainable materials, and renewable energy in the housing sector. 42 3.1 ACTION D: CUT OPERATIONAL ENERGY AND MATERIAL-BASED EMISSIONS Reducing emissions from housing construction and operation through passive design and low-carbon materials is a cost-effective path to long- term sustainability. KEY RECOMMENDATIONS: 1. Use low-carbon materials and passive design. Incorporate energy-saving materials and passive cooling strategies from the outset of housing design and construction. 2. Strengthen appliance standards. Revise SNI to require energy-efficient appliances and align with green building certification. 3. Standardize green housing prototypes and retrofit guidelines. Mandate and disseminate simple, ready-to-build green housing designs. 3.1.1 Intervention Rationale affordability, they have the highest embodied energy as they are produced through fossil-fueled high-temperature Indonesia’s affordable housing sector offers significant firing. Alternatives like hollow concrete blocks and potential for climate mitigation. In a typical KPR Subsidi Autoclaved Aerated Concrete Blocks, now used in over house, it is estimated that 21 percent of emissions come from 65% of surveyed homes (all developer-built), offer embodied sources, while 79 percent result from operational significantly lower emissions, are lighter in weight, and energy use. While each housing unit emits a relatively reduce structural loads and transportation energy.80 Scaling modest 2 to 3 tons of CO2 per year, the impact becomes up the use of these materials can reduce emissions while substantial when considering the scale, as approximately supporting local innovation and strengthening domestic 200,000 units are delivered annually through developer- building material industries. led housing programs.79 Given the government's 3 million housing target by 2029, introducing targeted low-carbon Roofing materials also contribute significantly to a interventions in this sector are pivotal to meeting national home's carbon footprint. Metal sheets, commonly used climate targets. for affordability and ease of installation, have higher embodied energy compared to clay or concrete tiles. While Low-income housing can reduce embodied emissions lightweight and manipulable, metal roofing also amplifies by shifting to more sustainable construction materials. heat, increasing indoor temperatures and cooling demand. Indonesia’s vernacular architecture is low-carbon, locally Transitioning to more sustainable and thermally efficient sourced, and provides good thermal performance, but roofing options would further lower emissions while communities often prefer brick houses as a reflection improving occupant comfort. of modern trends.. While traditional red bricks remain common in Indonesia due to their availability and 79 GBPN Study, 2024, confirmed with EDGE 3.0 simulation 80 IFC - International Finance Corporation, “EDGE Materials Reference Guide.” RESILIENT FOUNDATIONS, GREEN FUTURES 43 Despite subsidized homes having a relatively low energy Lights consumption, future electricity demands keep growing. 10% The building sector accounts for about 29 percent of Indonesia’s energy-related emissions, a figure poised to grow with population increases and rising demand for AC Home 29% air conditioning in a warming climate. 81 In homes with Equipments 61% 1300 VA electricity connections, appliances such as TVs, refrigerators, and washing machines account for 61 percent of electricity consumption. Cooling is the next largest use, with air conditioning typically representing around 25 to 30 percent of total household energy use, while lighting Source: GBPN Study, 2024 makes up about 10 percent. By 2024, air conditioner penetration in KPR Subsidi homes has reached an average FIGURE 19. ELECTRICITY USE PROFILE IN KPR SUBSIDI HOMES of 30 percent, underscoring the need for energy-efficient building strategies that also ensure thermal comfort82. Material use trends show growing interest in sustainable alternatives. Over 35% of homes surveyed use concrete Energy-efficient building design is critical to managing blocks and nearly 30% use AACB, both with lower rising cooling demand. Electricity use is shaped by the air embodied energy than red bricks. Roofing choices are also conditioner's coefficient of performance (COP), capacity, shifting, but over 40% of homes still use metal sheets, frequency of use, and room size. Designing homes to reduce despite clay and concrete tiles offering lower emissions and the cooling load through insulation, ventilation, shading, better insulation83. and orientation can reduce reliance on mechanical cooling and enhance thermal comfort affordably. Sustainability must be embedded across the entire housing lifecycle. Green, resilient housing requires attention from Current housing designs prioritize costs over performance, design and construction to occupancy. Nearly 90% of compromising livability. Developers often meet price homeowners modify their homes—often adding kitchens caps by minimizing construction standards, sidelining or porches—within two years, potentially undermining energy efficiency. Yet many energy-saving strategies such original energy performance. Future designs must anticipate as improved insulation, passive ventilation, and better and integrate such needs from the start84. layout can be implemented at low cost, boosting household comfort and reducing utility bills. Government leadership is essential to drive the energy- efficient housing transition. To meet the IGAHP net-zero Addressing the incentive gap between developers and housing emissions goal by 2050, Indonesia must establish residents is crucial to scaling the adoption of energy- energy-efficient affordable housing as the default offering. efficient and climate-resilient housing. While homeowners Clear policy direction, financial incentives, and developer benefit from lower energy costs, developers lack a direct engagement are key to transforming market norms and return on investment in energy-efficient features, especially accelerating the shift to sustainable, resilient housing. in non-rental housing markets. Incentive structures and regulatory nudges are needed to make efficiency a shared value proposition. 81 Climate Transparency, “Climate Transparency Report 2022: Comparing G20 Climate Action. Indonesia.” 82 GBPN Study, 2024 83 GBPN Study, 2024 44 3.1.2 Intervention Rationale in construction cost, these solutions improve thermal comfort and reduce long-term cooling needs86. 1. Prioritize Low-Carbon Building Materials in Affordable Housing 3. Combine Passive and Active Systems to Maximize Incentives need to be established to catalyze the use of Energy Savings low-embodied carbon materials within the SNI framework Energy-efficient utilities complement passive design and to encourage developers to adopt green certification strategies and could be actively promoted. Active systems systems. Contrary to common belief, materials such as like LED lighting, ceiling fans, water-efficient fixtures, AAC blocks and concrete bricks are competitively priced and biofilter septic tanks reduce utility costs and improve with traditional red bricks and are increasingly being household efficiency. Photocell sensors for outdoor lighting adopted in the market. Developer cost sensitivity makes and waste sorting bins further enhance sustainability. these low-carbon options viable for mainstream adoption. Promoting energy-efficient appliances can be done through To accelerate this shift, the Government could formalize the purchase incentives or appliance replacement programs, use of low-embodied carbon materials in national building as seen in the example from the Buenos Aires slum codes (SNI) and green certification systems, while offering upgrading project. recognition or incentives to “green developers.” Integrating rooftop solar and energy-efficient appliances Material choice can drive significant emission reductions. into KPR Subsidi housing presents a powerful opportunity Replacing red bricks with gypsum concrete panels could to reduce carbon emissions at scale. Annual CO2 reductions cut GHG annual emissions by approximately 89,000 are substantial based on an estimate annual KPR Subsidi tCO2, while switching to AAC blocks could achieve volume of 200,000 units: (i) rooftop solar installations can even greater emission savings of up to 120,000 tCO2 per deliver 25% energy savings, avoiding an estimated 30,900 year . Additional emissions reductions can be realized by 85 tons of CO2; (ii) efficient appliances contribute to a further sourcing materials locally (within a 1,000 km radius per 14,800 tons of CO2 savings through 20% energy reductions; BGH requirements) and incorporating recycled content, (iii) improved lighting systems offer 38% energy savings, particularly in programs like BSPS, where construction cutting emissions by 9,700 tons; and (iv) energy-efficient methods allow for greater flexibility. See Annex 2 for list of fans can lower emissions by an additional 1,300 tons with embodied energy of different construction materials. a 25% reduction in usage. Together, these measures not only enhance household affordability through lower utility 2. Standardize Passive Design for Energy Efficiency bills but also position Indonesia’s affordable housing sector and Comfort as a key contributor to national climate targets. Promote passive design as a low-cost, scalable energy solution. Passive strategies, such as reflective roofs, 4. Scale Integrated Green Prototypes and Retrofit cross-ventilation, shading devices, and low U-value wall Strategies materials, cut indoor temperatures and reduce energy The government’s homeownership program is already demand without relying on mechanical systems. These well-positioned to achieve BGH basic green certification measures are especially suitable for Indonesia’s hot climate (Pratama level) without requiring additional investment. and low-income housing. Through collaboration with the Global Building Performance Network (GBPN), the MoHS has developed Small design changes yield measurable impact. Simple standardized prototype designs for developer-built passive interventions can reduce annual operational units under the KPR Subsidi scheme that comply with emissions by 0.1 tCO2 per unit. With only a 3.7% increase 84 GBPN Study, 2024 85 Carbon finance opportunities in the affordable housing sector in Indonesia analyzed by South Pole (2025). Refer to Annex 8 86 Cost of roof coating and shading as a simple passive design measure, as per EDGE 3.0 RESILIENT FOUNDATIONS, GREEN FUTURES 45 14.00 12.80 12.00 Energy use/ saving (kWh / m2 / year) 10.00 7.74 8.00 6.00 4.00 3.20 2.70 2.00 1.55 1.03 0.60 0.15 0 Energy E cient Energy Lighting Onsite Renewable E cient Refrigerator and Ceiling Fans (-25%) System incl. (38%) Energy (-25%) - low Clothes Washing Machines (-20%) FIGURE 20. ENERGY SAVINGS FOR IMPLEMENTING ENERGY-EFFICIENT APPLIANCES (SOUTH POLE) the minimum technical requirements for Pratama improvements or spatial expansions—offers a scalable certification, including energy efficiency and construction solution to enhance livability while reducing environmental quality. Achieving higher tiers of certification—Madya impact. For quality upgrades, the BSPS program can play (intermediate) and Utama (advanced)—would require a pivotal role by incorporating structural strengthening incremental construction investments to meet enhanced and passive climate adaptation features into its criteria. green performance standards. Current estimates suggest an For expansions, integrating green building guidelines helps additional cost of approximately 2.5% (IDR 4.5 million) ensure that added rooms or income-generating rental for Madya certification and 5.5% (IDR 10 million) for spaces maintain energy and resource efficiency. Utama certification. The benefits of even modest green retrofits are significant. Ready-to-build green housing prototypes can simplify As demonstrated in pilot studies in Palembang (see details compliance with construction standards and quality in Annex 6), investments that increase costs by only 6 to requirements. Government-developed designs and 7 percent can yield monthly savings of USD 15 to 30 or prototypes that integrate BGH criteria can ease adoption 2.5 to 5 percent of household income through reduced and lower costs for households and developers. To electricity and cooling needs87. These savings not only encourage broader market use and implementation, these improve affordability but also contribute to national prototypes should be made publicly accessible, actively energy efficiency and climate goals. Moreover, features promoted and supported through training initiatives. such as backyard rental units and retail spaces can boost household incomes, making retrofits a financially viable Retrofitting represents a high impact, yet largely and socially empowering intervention. Simple passive underutilized strategy for improving the quality, efficiency, design strategies—such as improved ventilation, reflective and resilience of Indonesia’s existing housing stock. Given roofing, and shading—offer immediate, low-disruption that the vast majority of Indonesia’s low-income households upgrades that can be tailored to Indonesia’s diverse live in self-built homes that were not constructed with climates, providing a strong foundation for more resilient thermal comfort, disaster resilience, or long-term durability and inclusive housing development. in mind, retrofitting these homes—either through quality 87 Household income assumed at IDR 10 million (approximately USD 610) per month, in line with the GoI credit-linked home ownership program eligibility criteria. 46 Adopt guidelines to real-world housing variations. Housing microfinance pilots conducted by MoHS in 2024-2025 revealed that rigid retrofit standards often fail to match household needs. More tailored guidelines allowing for flexible, context-specific assessments would enable more practical, beneficiary-led green retrofits to take place. Outdoor lamp sensor +2 points Land Management NO. CRITERIA MAX POINTS Shading & edible POINTS OBTAINED vegetation 1. Site Management 8 3 2. Private Green Open 2 2 Space (GOS) 3. Carport Land Provision 8 8 4. Outdoor Lighting 2 2 System Green area 15.22% TOTAL 21 15 Carport land does Albedo 0.58 not take public land Light-colored concrete pavement and roof Achieves maximum lighting Room depth does Energy Use Efficiency strength as per standard not exceed 2x (LED lights) | +5 points the height of the NO. CRITERIA MAX POINTS window head POINTS OBTAINED 1. Building Envelope 16 10 Shading 2. Air Conditioning System 15 15 3. Lighting System 10 10 4. Electrical System 5 0 TOTAL 46 35 Designed without requiring AC WWR 9.9% FIGURE 21. EXAMPLE OF GREEN HOUSING PROTOTYPES CURRENTLY BEING DEVELOPED BY MOHS (SEE ANNEX 3) RESILIENT FOUNDATIONS, GREEN FUTURES 47 3.2 ACTION E: EXPLORE OPPORTUNITIES TO INTEGRATE ROOFTOP SOLAR PHOTO VOLTAIC PANELS INTO THE AFFORDABLE HOUSING SECTOR Harnessing rooftop solar energy in the low-income housing sector can reduce emissions, lower energy bills, and strengthen Indonesia’s renewable energy transition. KEY RECOMMENDATIONS: 1. Test rooftop rental models for solar PV on the public and rental housing sector. 2. Assess Government housing designs to meet rooftop solar technical requirements. 3. Pilot rooftop solar in low-income housing, prioritizing areas outside the Java–Bali grid. 3.2.1 Intervention Rationale intermittent access to electricity in regions beyond Java, Bali, and Sumatra. Indonesia has made rooftop solar a key pillar of its energy transition. National targets aim to scale solar capacity from Solar integration in subsidized housing could yield major 900 MW in 2023 to 3,375 MW by 2025, with mandates for climate benefits. The One Million Homes Program could 30 percent rooftop use on public buildings and 25 percent cut emissions by up to 34 million metric tonnes of CO2, on state-owned enterprises. Indonesia Electric Company, 88 and each solar-equipped house can save 22.4 metric Perusahaan Listrik Negara (PLN) targets 400 MW of tonnes.92,93 In total, social housing could host 1.3 GW of Rooftop Solar Photovoltaic or RSPV, but only 120 MW rooftop solar annually, advancing both renewable energy had been installed as of February 2024. 89 Despite interest and emissions goals. from developers and government bodies, systemic barriers Despite Indonesia’s strong technical potential for RSPV, have slowed adoption. These include the elimination of net structural barriers in the energy and regulatory landscape metering, introduction of restrictive development quotas, continue to constrain its adoption. The state utility PLN’s oversupply and financial constraints, regulatory company, PLN, faces excess generation capacity in the uncertainty, and limited access to financing and skilled labor. Java-Bali and Sumatra grids, limiting the integration of new RSPV holds strong technical potential in affordable housing. renewables. This is exacerbated by long-term take-or-pay While Indonesia’s solar irradiation is moderate (3.6–6 contracts with Independent Power Producers (IPPs), which kWh/m²/day), its equatorial location and extensive rooftop require PLN to purchase electricity regardless of demand. area provide a strong foundation. Urbanization, which Meanwhile, coal remains artificially competitive due to is projected to surpass 70% by 2045, adds momentum policy, which keeps domestic coal prices low and weakens for scaling solar in residential areas. 90 Additionally, the case for renewables. Currently, 85% of Indonesia’s RSPV could serve as a backup energy source and address power capacity is fossil-fuel-based.94 Although the energy 88 President Regulation No. 22 of 2017 on the General Plan on National Energy (“PR 22/2017”) 89 Mission consultation with MEMR 90 Roberts, Gil Sander, and Tiwari, Time to Act. 91 Accenture Strategy & Consulting, “Indonesia System Value Analysis.” 92 WB’s Task Team Analysis using IFC’s EDGE 93 Herry Trisaputra, “Indonesia Green Affordable Housing Program (A New Initiatives in Greening 1 Million Houses in Indonesia).” 94 Aditya, Wijayanto, and Hakam, “Advancing Renewable Energy in Indonesia.” 48 mix is expected to shift by 2030, PLN still plans to expand for utilities. While no regulatory barriers currently exist, coal, oil, and gas infrastructure. 95 Its pledge to halt new successful implementation depends on strong commitment coal-fired power plants has been diluted by Presidential from both PLN and PT PLN Icon Plus. Regulation No. 112/2022, which permits exceptions under Scaling rooftop solar will require coordinated certain conditions. Consequently, fossil fuel capacity will action. Government alignment, targeted incentives, continue to grow. Additionally, requirements mandating and utility engagement are key to unlocking that Government-funded solar projects use at least 40% RSPV’s full potential in affordable housing. domestically produced components raises costs and complicates the scalability of RSPV deployment.96 3.2.2 Intervention Approaches A rooftop rental model offers a promising solution. In this 1. Test Rooftop Rental Models to Accelerate RSPV arrangement, PLN or its subsidiary, PT PLN Icon Plus, Deployment on Public Buildings would lease rooftop space from property owners and The rooftop rental model is a viable business case for directly invest in solar installations. Although current scaling RSPV on affordable housing and public buildings net metering regulations provide little incentive for in Indonesia.97 Under this model, investment is shifted to homeowners, this model could still be financially attractive PLN and its subsidiary, PT PLN Icon Plus, allowing them Kalimantan Lion share of coal 52 6 Sulawesi Only Region with reserves/ mines limited by non-variable concentrated in renewable potential Kalimantan/ Sumatra. 15 15 3 0.01 Sumatra 5 GW 2.2 GW Papua 6 GW 1.7 GW 70 16 9 - 5.7 0.07 16 GW 5.2 GW 0.2 GW 0.8 GW Java & Bali* Maluku 44 17 7.2 3.5 21 1.1 54 GW 9.6 GW 0.3 GW 1.2 GW Limited in space due to high population density; currently imports coal from Kalimantan/ Sumatra; Solar PV Potential (GW) Coal Reserves rooftop solar potential. Geothermal Potential (GW) Total Installed Capacity 2030 (GW) Hydro Potential (GW) Total Renewable Capacity 2030 (GW) FIGURE 22. INSTALLED CAPACITY & RESOURCE POTENTIAL BY ISL AND IN INDONESIA 91 95 Accenture Strategy & Consulting, “Indonesia System Value Analysis.” 96 Hamdi, “Indonesia’s Solar Policies.” 97 Castalia study RESILIENT FOUNDATIONS, GREEN FUTURES 49 to benefit from reduced grid generation costs. Building strong, oriented to maximize sun exposure (ideally to the owners gain rental income or reduced power bills without north or slightly west), and free from shading. Roofs with the upfront costs. PT PLN Icon Plus oversees system low slope or flatter profiles are preferred. Common areas installation, operation, and negotiations with building such as parking structures or upgraded roofing materials owners, bundling rooftops into aggregated contracts can also help maximize viable rooftop space. with PLN. It retains system ownership, avoiding lengthy 3. Pilot the Rooftop Rental Model in Jakarta procurement, and leases the RSPV systems to PLN for a fixed annual fee in exchange for all generated electricity. Jakarta has shown strong readiness, setting a 200 MWp RSPV target by 2050 and already installing 3.1 MW 2. Assess Design Modifications in Low-Income across 136 public buildings. It plans to include RSPV in Housing to Meet Technical Criteria for RSPV all new schools and retrofit between 20 and 30 buildings While public buildings are easier to integrate into the model, annually. Over 400 buildings have rooftop capacity above affordable housing can also participate if implementation is 100 kW, offering a combined technical potential of 77 MW. scaled at the project or neighborhood level. PT PLN Icon Jakarta’s land scarcity and high costs further enhance the Plus requires a minimum of 425 m² of contiguous rooftop appeal of rooftop solar. Under this model, Jakarta would to install 100 kW of solar. Roofs must be structurally lease roof space to PT PLN Icon Plus, which installs the PV development partner which can provide capital and equipment Fixed rooftop rental payment Lease to Icon Plus for in the form of a reduction in use of RSPV (including power bills. Public Building roof rent cost) owners receive CER credits Public Building owners LEASES RSPV UNITS AND RETAILS OWNS AND OPERATES RSPV UNITS, PROVIDES ROOFTOP SPACE TO HOST ELECTRICITY FROM RSPV UNITS AND PAYS ROOFTOP RENT RSPV UNIT Use of RSPV Rooftop space usage Electricity FIGURE 23. ROOF TOP RENTAL BUSINESS MODEL 98 98 Castalia Advisory, “Affordable Housing and Public Buildings as Renewable Energy Power Grid in Indonesia,” October 2024. 50 systems and leases them to PLN. The city would benefit 5. Policy Support to Enable Broader RSPV Adoption through electricity bill reductions and emissions reduction Once successfully piloted, the rooftop rental model could certificates to meet green building standards (e.g., EDGE, be scaled up to significantly expand RSPV installations, Greenship, BGH). delivering mutual benefits for PLN, Icon Plus, and building 4. Explore RSPV application where it Undercuts owners. This approach supports New, Renewable Energy, Local Power Generation Costs and Energy Conservation or EBTKE’s targets of reaching 1,004 MW of rooftop solar capacity by 2025 and 1,593 Rooftop rental is often cheaper than utility-scale solar due MW by 2028. Policy support is critical to facilitate this, to avoided land acquisition costs and reduced transmission including formalizing MPW and Ministry of Energy and losses. In many regions, and especially outside Java-Bali, Mineral Resources’ (MEMR) endorsement of the model, RSPV is already more cost-effective than PLN’s current cost legalizing rooftop leasing, and issuing technical guidelines of generation (BPP). A cost comparison map shows large to streamline implementation. swaths of Indonesia (highlighted in red/pink) where RSPV is cheaper than conventional power. PLN should prioritize RSPV expansion in these areas, particularly where utility- scale solar is not feasible. RSPV LCOE higher cost than BPP 2020 RSPV LCOE lower cost than BPP 2020 FIGURE 24. MAP OF RSVP COSTS ACROSS INDONESIA. RESILIENT FOUNDATIONS, GREEN FUTURES 51 3.3 ACTION F: BEYOND INDIVIDUAL HOUSING: ADVANCING SUSTAINABILITY THROUGH NEIGHBORHOOD AND CITY-SCALE SYSTEMS Sustainable infrastructure and land use at the neighborhood scale can deliver greater climate gains through density, mobility integration, and nature-based solutions. KEY RECOMMENDATIONS: 1. Promote compact, higher-density housing typologies to limit land use and urban sprawl. 2. Integrate housing with transit through TOD to reduce congestion and commute times. 3. Invest in communal renewable energy and green infrastructure to lower emissions and boost climate resilience at scale. 3.3.1 Intervention Approaches KPR Subsidi program, while successfully providing affordable housing at scale, has pushed housing production Climate adaptation in housing must go beyond the to periphery. The price control mechanism that enables building scale and address housing typology, location, subsidized housing to be continuously priced 30% of the and the broader urban system. While previous discussions lowest market price (Figure 25), has pushed developers to have focused on building-level solutions, achieving long- build further to reduce land acquisition costs. In 2019, more term sustainability and resilience requires addressing than 90% of subsidized housing development is located in how housing interacts with transportation, land use, and rural or peri-urban areas, despite the highest need being in environmental systems. urban centers.99 Currently, 99% of Government-subsidized The dominance of low-density, single-family subsidized housing consists of single-story row houses occupying housing contributes to urban sprawl and land inefficiency. at least 60 m² of land per unit.100 This approach is land- 700 Millions 2% 1% 2% 2% 1% 600 5% 580,93 588,84 7% 551,86 560,60 568.97 541,90 6% 3% 516,57 500 - 471,09 484,11 445,96 400 Price (IDR) 300 200 6,33% 0% 7,74% 100 5,53% 5,62% 0% 5,32% 6,40% 168,00 168,00 181,00 Subsidized homes 5,42% 148,50 158,00 - 120 126,50 133,50 141,00 141,00 Market-rate small homes 0 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 FIGURE 25. AVERAGE RESIDENTIAL PRICE GROWTH COMPARISON BETWEEN SUBSIDIZED RATE AND MARKET RATE IN JABODETABEK 99 NAHP Housing Location Study by World Bank Task Team 100 FLPP Realization 52 Estimated Commuting-Related Housing Carbon Emission Medan Metro Area 9% 91% Bandung Metro Area 15% 85% urban core Jakarta Metro Area 17% 83% outskirts FIGURE 26. ESTIMATED COMMUTING-RELATED HOUSING CARBON EMISSIONS intensive, poorly integrated with transit infrastructure, and spend more than 9% of their income on transportation.103 slow to meet urban demand. This highlights a trade-off: while housing may be more affordable in the periphery, transportation costs are Highway infrastructure is a key driver of suburban sprawl significantly higher. and emissions. In the Jakarta Metropolitan Area, every kilometer of highway ramp expansion contributes to 1.6% Urban sprawl driven by low-density development and of urban land growth in surrounding suburbs. 101 Suburban highway expansion has severe environmental consequences. areas, which are heavily reliant on private vehicles, are The unchecked expansion of housing into peri-urban and estimated to contribute over 80% of transit-related carbon rural zones contributes to deforestation, reduced watershed emissions in the region. 102 functionality, and increased dependence on private vehicles. In the Upper Citarum Watershed, forest loss and Transport expenditures tend to be higher in peripheral increased built-up areas have degraded the land’s ability to areas due to longer commuting distances. In the Jakarta manage water, increasing flood risks in low-lying areas.104 Metropolitan Area, 32% of commuters living in the As permeability declines and groundwater extraction rises, periphery spend more than 9% of their monthly income on urban settlements face higher risks of subsidence and commuting, while another 30% spend between 6–9%. In water insecurity. contrast, only 22% of commuters residing in Jakarta’s core Transport Expenditures to Monthly Income per Capita in Jakarta Metro Area periphery 5% 12% 20% 30% 32% core 13% 20% 23% 22% 22% 0 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Percent of Commuters <2% 2%-4 4-6% 6-9% >9% Transit Expenditures to Monthly per Capita 101 Pratama, Yudhistira, and Koomen, “Highway Expansion and Urban Sprawl in the Jakarta Metropolitan Area.” 102 World Bank Urban Team simulated Business as Usual Spatial plan to predict urban expansion by 2030 in metro areas 103 Badan Pusat Statistik, “Statistik Komuter Jabodetabek 2023.” 104 Agaton, Setiawan, and Effendi, “Land Use/Land Cover Change Detection in an Urban Watershed.” RESILIENT FOUNDATIONS, GREEN FUTURES 53 Empirical evidence links sprawl with significant 6 cities, built-up area expansion has outpaced population environmental degradation in Indonesian cities. In Makassar, growth, signaling a risk of vacant housing. Conversely, land use change and sprawling urban growth correlate Tier 1–3 cities are experiencing rapid population growth with an 85.9% deterioration in environmental quality.105 but have limited capacity for further horizontal expansion Similarly, in Semarang, over 30 km² of farmland and 14 km² (see Annex 5 for urban tier categorization).107 Without of forests were lost to urban and industrial development densification, these cities risk overcrowding and inefficient between 2006 and 2015. This pattern undermines carbon resource use. This analysis shows that in the last decade, sequestration, food security, and local climate regulation. 106 Indonesia has been experiencing a location mismatch of settlement growth and population housing needs. There is a growing mismatch between housing supply and demand across urban hierarchies in Indonesia. In Tier 4 to Multidistrict Metro Core Multidistrict Metro Periphery-Urban Single-District Metro Multidistrict Metro Periphery-Rural Population Non-Metro Urban Percent Change Non-Metro Rural Land Cover Percent Change 0% 5% 10% 15% 20% 25% FIGURE 27. CHANGE IN BUILT -UP AREA VERSUS POPUL ATION GROW TH 3.3.2 Intervention Approaches 2. Transition from Low-Density Row Housing to Higher-Density Typologies 1. Promote Mixed-Use Development and Integrate Green Spaces in Housing Projects Shifting from low-density housing toward compact, mid- to high-rise developments in Government housing programs Enabling mixed-use development in government housing can curb urban sprawl, conserve land, reduce deforestation, programs can shorten travel distances, reduce emissions, and enhance infrastructure delivery. Infill and brownfield and improve the quality of life for residents. Single-use redevelopment, through reconfiguring underutilized sites, zoning has led to fragmented residential enclaves that revitalizing old buildings, and optimizing public land, are disconnected from jobs, services, and amenities. should complement greenfield expansion. However, two Globally, integrating green spaces and parks into urban key barriers remain: design has been shown to offset 2.3 to 3.6% of citywide carbon emissions.108 105 Surya et al., “Land Use Change, Urban Agglomeration, and Urban Sprawl.” 106 Kelly-Fair et al., “Analysis of Land Use and Land Cover Changes through the Lens of SDGs in Semarang, Indonesia.” 107 World Bank Task Team Analysis using GHS-Built Up Surface Grid (2010-2020) and BPS 108 Sun et al., “ The Impacts of Urban Form on Carbon Emissions.” 54 • Land constraints in urban centers limit space for 2050.109 Dense, walkable neighborhoods with connected large-scale vertical housing projects. road networks encourage low-carbon travel modes.110 Jakarta’s experience with TOD demonstrates promising • Regulatory limitations, including outdated height outcomes: between 2013–2020, five of eight TOD zones restrictions and a lack of enabling codes, discourage saw increased residential use, and peripheral TODs saw mid-rise construction. For instance, only Jakarta more workplaces and public facilities.111 Additionally, permits four-story simple housing, while other cities TransJakarta’s Bus Rapid Transit system has helped shift often restrict it to two stories. Building codes subject commuter behavior toward public transport, supported by mid-rise units like high-rises, increasing costs and affordable fare structures. complexity. Addressing these barriers is essential to support the development of space-efficient 4. Invest in Sustainable Infrastructure at the housing typologies. Neighborhood-Scale 3. Link Housing Development with Transit-Oriented Communal green infrastructure like parks, tree-lined streets, Development (TOD) and vegetated corridors lower neighborhood temperatures and energy demand while offering recreational and health Integrating housing with public transit, pedestrian benefits. Blue infrastructure (wetlands, bioswales, retention pathways, and cycling infrastructure helps reduce car ponds, permeable pavements) helps to manage stormwater, dependency and lower transport-related emissions. reduce flood risk, and enhance resilience. Neighborhood- System dynamics modeling suggests that TOD could scale renewable energy systems, such as shared rooftop reduce fuel use and emissions in Indonesia by 34% by solar on schools or markets, offer economies of scale and Missing Middle Housing Small scale Medium scale Large scale MULTI-FAMILY 6 APARTMENT: HIGH- TRIPLE DECKER RISE VERTICALS Mini walk-up Apartments for large- apartment for multi- sized plots ROW TOWN-HOUSES families in small plots Single-family 2-floors single-family 4 with less land required 2 5 APARTMENT: 3 LOW-RISE VERTICALS 1 MULTI-FAMILY Walk-up apartments for LANDED HOUSES COURTYARD HOUSES medium-sized plots Single-family Community-oriented cluster Typical KPR subsidy houses for medium plot subdivisions FIGURE 28. MISSING MIDDLE HOUSING IN INDONESIA 109 Sukarno, Matsumoto, and Susanti, “Transportation Energy Consumption and Emissions - a View from City of Indonesia.” RESILIENT FOUNDATIONS, GREEN FUTURES 55 reduce grid reliance. Paired with battery storage and smart scale, climate action must emphasize compact, mixed-use management, they can boost energy security and accelerate development to curb urban sprawl, conserve green and the shift toward low-carbon, climate-resilient communities. blue spaces, and reduce travel-related emissions. Enhancing urban microclimates through green infrastructure and In conclusion, the pathway to effective climate mitigation promoting solar PV adoption via community-scale systems in Indonesia’s housing and urban sectors requires a multi- and spatial suitability mapping further strengthens climate scalar approach that integrates building-level efficiency with resilience. Collectively, these interventions highlight that broader neighborhood and settlement-level planning. At the targeted, context-specific strategies—coordinated across housing level, priority actions include the use of low-carbon, sectors and scales—are essential to reducing emissions, locally sourced materials, adoption of energy- and water- improving resource efficiency, and creating livable, future- efficient appliances, integration of passive design strategies, proof communities. See Table 2 which summarizes Chapter and enabling rooftop solar installations through technical 3 Climate Mitigation strategies. design adaptations. At the neighborhood and settlement MITIGATION GOALS GHG EMISSION WATER & ENERGY SOLAR PV ADOPTION AS INTERVENTION SCALE REDUCTION EFFICIENCY RENEWABLE ENERGY SOURCE Use low-carbon and locally sourced Prioritize energy-efficient Implement rooftop rental construction materials appliances (e.g., LED lighting, models in public housing and (e.g., replacing red bricks to AAC high COP AC, smart meters) government buildings to increase bricks sourced within 1,000km) access to solar PV systems Housing-Level Incorporate passive design Prioritize water-efficient Adapt low-income housing strategies (e.g., natural lighting and appliances (e.g., dual-flush designs to meet technical cross-ventilation to reduce cooling toilets, low-flow faucets, smart requirements for solar PV and lighting loads) water meters) installation (e.g., flat or low- slope roofs, structurally sound rooftops, appropriate orientation) Promote compact urban Enhance urban microclimate Install community-scale development and preserve natural and reduce cooling needs with solar PV systems on shared areas (e.g., through medium to high green-blue infrastructure (e.g., infrastructure (e.g., communal Neighborhood & density housing development and street trees, urban park, retention parking lots, public facilities, conservation of green and blue areas) ponds) community centers) Settlement-Level Reduce sprawl and travel demand Optimize urban form to improve Promote solar PV adoption in (e.g., mixed-use zoning, transit- energy performance (e.g., high-potential areas, especially oriented development, and building orientations and spacing outside the Java-Bali grid, by investment in low-emission transport to capture prevailing winds and integrating solar suitability modes like walking, cycling, EVs, and optimize street shading) mapping into spatial planning public transit) TABLE 2. SUMMARY OF CLIMATE MITIGATION STRATEGIES BY SCALE 110 Sun et al., “ The Impacts of Urban Form on Carbon Emissions.” 111 Hasibuan and Mulyani, “Transit-Oriented Development: Towards Achieving Sustainable Transport and Urban Development in Jakarta Metropolitan, Indonesia.” 56 04 Cross-Cutting Action Framework Several cross-cutting interventions at the institutional level can further support climate integration into the Indonesian affordable housing sector. RESILIENT FOUNDATIONS, GREEN FUTURES 57 4.1 ACTION G: BUILDING RESILIENT AND GREEN HOUSING CONSTRUCTION DESIGN, PERMITTING, MONITORING AND CERTIFICATION SYSTEMS Effective design, permitting, quality control, and certification frameworks are essential for scaling resilient and green housing programs across the country. KEY RECOMMENDATIONS: 1. Establish integrated design: seismic, flood, thermal resilient, and green sustainable prototypes and retrofit guidelines, including universal accessibility requirements. 2. Apply risk-informed planning and construction permitting using integrated spatial data to reduce disaster exposure. 3. Enforce construction quality through a robust, tech-enabled QAQC system with cross- agency coordination. 4. Strengthen and scale the BGH certification system to align with international standards. 4.1.1 Intervention Rationale interoperability, unified governance, and consistent updating cycles, which hampers coordinated risk analysis Existing housing design standards lack flood and thermal and timely preemptive action. As a result, resources stress considerations, and leave out the needs of a rapidly are used inefficiently, and reconstruction costs escalate aging population. Although earthquake-resistant housing following disasters. designs are relatively well established and is embedded in formal permitting processes such as the PBG, flood Institutional fragmentation limits integrated planning. and thermal stress resilience remain largely absent from National-level mandates from MoHS, Bappenas, most prototypes, despite the rising frequency and severity BNPB, MoEF, and ATR/BPN overlap but remain poorly of such events under a changing climate. Furthermore, coordinated. At the local level, agencies responsible for current design standards do not incorporate universal housing, disaster risk reduction, and planning typically design principles necessary to support an aging society. work in isolation, weakening the effectiveness of climate Indonesia entered an aging population phase in 2022, with and disaster-resilient urban development. See Annex 7 for projections indicating that 20.3% of the population will be institutional silo breakdown analysis. elderly by 2045. 112 Construction standards and mechanism exist but are Uncoordinated systems heighten housing vulnerability to undermined by weak enforcement and fragmented disaster risks. Key agencies responsible for housing, spatial responsibilities. Standards are set by DG Cipta Karya, planning, and disaster management currently operate with training by DG Bina Konstruksi, and SLFs (occupancy separate and uncoordinated data systems. For example, certificates) are issued by local governments, yet these BNPB relies on InaRISK 113 for hazard mapping and DiBi114 interdependent functions operate in silos.117 SLFs are for disaster statistics; the MoHS uses platforms such as intended to verify minimum construction quality but its HREIS , Sipetruk, and Sikumbang to monitor housing 115 enforcement is weak and mainly limited to developer-built and construction; while ATR/BPN manages spatial data housing. In 2020, only 10% of local governments had through the GISTARU116 system. These systems lack capacity to issue SLFs, and even some SLF-certified homes 58 failed to meet technical standards, indicating weaknesses in Green building certification systems are incomplete. the verification process. Indonesia has three green certification systems, each with notable gaps: Government housing programs show systemic enforcement gaps. In the KPR Subsidi Program, developers often use • BGH integrates construction quality via SLF and low-quality materials to stay within price caps. Supervisors emphasizes affordability but suffers from limited employed by developers may overlook poor practices, and scalability. Certification relies on local governments, construction workers are often untrained. Consequently, most of which lack capacity. Only 20 BGH assessors residents expect poor quality in subsidized housing. World exist nationwide. Adoption is voluntary and slow Bank assessments found that only 16% of BP2BT homes without incentives, and developers face costs despite (2019) and 11% of BSPS retrofitted homes (2018) met the “no-cost” certification claim. minimum standards, evidence of systemic issues in quality • EDGE provides a strong carbon-savings calculator and assurance. Please refer to Annex 4 for further details. user-friendly interface but does not assess construction SiPetruk offers promise but remains underutilized. quality or location risks. To date, 33,352 units have Launched in 2020, SiPetruk requires developers to submit been certified, including 11,324 for low-income construction documentation and structural photos to housing. qualify for subsidies. While it could significantly improve • GREENSHIP includes location suitability but lacks oversight, adoption remains limited due to developer construction quality checks and GHG accounting. resistance and lack of regulatory enforcement. It has certified 6,817 units, but its high-cost limits broader adoption. ASPECTS EDGE GREENSHIP BGH Monitors and audits green standards Yes Yes Yes No No Requires SLF to ensure Monitors and audits construction quality construction quality (still difficult to obtain) Incorporates location consideration No Yes No (distance to public facility, public transport & basic infrastructure) Calculates carbon savings Yes No No Yes, but potentially Yes, but potentially Lack resource for Scalable expensive expensive robust monitoring FIGURE 29. COMPARISON OF GREEN CERTIFICATION SYSTEMS 112 Badan Pusat Statistik, “Statistik Penduduk Lanjut Usia 2023.” 113 InaRISK is a disaster risk assessment portal developed by BNPB to provide spatially integrated data on hazard exposure, vulnerability, capacity, and disaster risk mitigation recommendations. https://inarisk.bnpb.go.id/ 114 DiBi is a disaster loss database managed by BNPB, documenting historical disaster events in Indonesia. https://dibi.bnpb.go.id/ 115 Housing and Real Estate Information System (HREIS) is an integrated housing data platform developed by MPWH that consolidates housing supply, demand, pricing, and financing data across government agencies. https://hreis.pu.go.id/portal/ 116 GISTARU is a web-based geographic information system managed by ATR/BPN to standardize spatial planning data and enhance public access to regional land-use regulations. https://gistaru.atrbpn.go.id/ 117 Directorate General of Cipta Karya (Human Settlement) and Directorate General of Bina Karya (Construction Development) are both under the MPW. RESILIENT FOUNDATIONS, GREEN FUTURES 59 BGH can be strengthened to become a comprehensive being the most frequent disaster in Indonesia, flood national standard. As the Government’s preferred resilience still lacks a formal design standard. Informal certification, BGH has potential but risks falling short solutions—such as raising floors with debris or building of international benchmarks. It must be improved by stilt homes—exist in many communities but remain addressing capacity constraints, integrating robust quality undocumented, inconsistent, and inadequate for long- assurance, and including location risk criteria. Doing term resilience. A formal housing adaptation standard, so would enhance its credibility and usability for scaling incorporating wet-proofing, dry-proofing, and flood resilient, green housing nationwide. avoidance strategies, needs to be urgently developed and tested in vulnerable coastal and riverine settlements. At the same time, rising urban temperatures demand thermal- 4.1.2 Intervention Approaches resilient design, especially for low-income households that A comprehensive and mandatory regulatory approach must cannot afford mechanical cooling. Passive strategies like be positioned as the central priority for building climate cross-ventilation, reflective roofing, and roof insulation resilience in Indonesia's housing sector. Additionally, future are essential, low-cost options that can be mainstreamed building regulations and certifications should be carefully through standard prototypes. designed to prevent potential pitfalls. This necessitates Integrated retrofit guidance could help existing homes in streamlining and integrating disaster adaptation and climate achieving resilience and sustainability. The majority of mitigation measures throughout the entire development low-income households in Indonesia do not build new value chain, from design and planning, to construction, homes but instead expand or renovate incrementally, often certification, and occupancy. without technical guidance. Therefore, the development 1. Integrated design: seismic, flood, thermal of resilient housing prototypes must be complemented by resilient, and green sustainable prototypes clear, actionable retrofit guidelines. Many existing homes and retrofit guidelines, including universal lack structural integrity, thermal comfort, or climate accessibility requirements adaptation features. Programs like BSPS can play a pivotal Establish integrated, multi-hazard housing prototypes role in upgrading these homes by incorporating structural tailored to low-income households. While many housing reinforcement, energy efficiency, and passive climate prototypes have been developed in Indonesia, a more design. Retrofitting also opens opportunities for income integrated approach is required as low-income communities generation through additional rental units or retail spaces, increasingly face multiple, overlapping hazards. Rather than creating a win-win scenario for household resilience and treating each hazard in isolation, a consolidated package of improved livelihoods. resilient housing prototypes tailored to local risk profiles Universal design features must be embedded in all housing is needed, incorporating seismic, flood, and thermal-stress prototypes to accommodate Indonesia’s aging population. resilience. Integrating green and sustainable features is also Housing prototypes must ensure safety and accessibility for critical, not only to mitigate emissions but also to reduce the elderly and persons with disabilities, including features operational costs for low-income households. Moreover, like level entrances, grab bars, wider doorways, and non- prototypes should not be limited to landed housing slip flooring. These features are not luxuries but necessities alone; compact, land-efficient typologies that minimize that will protect the most vulnerable members of society. As commuting distance and support more sustainable urban the country seeks to build inclusive, disaster-resilient, and forms must also be promoted. sustainable housing for the future, universal accessibility Flood- and heat-resilient housing standards must be must be considered a core element of design for both new formalized and embedded in housing programs. Despite construction and retrofit. 60 2. Implement Risk-Informed Planning and Permitting planning and disaster systems will unlock real-time to Reduce Disaster Exposure analytics, improve compliance checks, and enable smarter, coordinated decisions. Integrate location suitability analysis into planning and permitting. Risk-informed housing development can reduce Clarify roles across disaster phases. Before disasters occur, household exposure to climate and disaster risks. While no the Government should focus on providing accurate location in Indonesia is risk-free, recent advances in GIS and accessible hazard maps, enforcing resilient building and multi-criteria analysis enable smarter site selection. standards, and conducting public awareness campaigns to Key datasets – from ATR/BPN’s GISTARU and BHUMI118 strengthen preparedness. During disasters, authorities must to BP Tapera’s SIKUMBANG, MoHS’ HREIS, and BNPB’s coordinate evacuation efforts, ensure the continuity of InaRISK – can guide planning and development toward critical infrastructure and services, and protect vulnerable safer sites. Embedding location suitability into the building populations. In the aftermath, government agencies should permit (PBG) process will help local governments prioritize lead housing reconstruction, ensuring that it is timely, safer development and mandate resilient design where inclusive, and aligned with resilience standards. Community hazards cannot be avoided. involvement is equally critical in preparedness planning, damage assessments, and ensuring that aid is distributed Empower local governments to act as gatekeepers of transparently and reaches those most in need. risk-informed development. Local governments must be equipped with the data, tools, and authority to deny 3. Enforce Construction Quality Through a Robust permits in high-risk areas, and to condition approval on QAQC and Digital Monitoring System disaster-resilient design (e.g., raised housing in flood zones, Build on NAHP’s successful QAQC model. The NAHP seismic reinforcement in earthquake zones). Spatial plans program significantly improved construction quality must reflect updated hazard maps, and local capacity must through a comprehensive QAQC system. Key features be strengthened to apply these insights consistently. included multi-stage, photo-based monitoring, a clear Address critical implementation barriers to risk- checklist, audits at multiple levels, and widespread training. informed development. Key challenges include limited IT Results showed a sevenfold improvement in BSPS housing infrastructure, inconsistent and outdated datasets, and quality, and a threefold improvement in BP2BT housing. uneven GIS skills at the local level. These gaps prevent Please refer to Annex 4 for further details on the learnings the effective use of spatial tools. Investments are needed from NAHP QAQC. in digital infrastructure, standardized data systems, and Institutionalize and incentivize the SiPetruk monitoring local technical training to institutionalize risk-informed platform. To scale construction quality enforcement, development. SiPetruk must be restarted and adopted across subsidized Leverage the Satu Data (“One Data” Indonesia policy for housing programs. Developers should be required to cross-sectoral data integration. The national “One Data” register and upload documentation, while authorities must policy can facilitate the interoperability of Government monitor compliance. Linking SiPetruk use to incentives— platforms through shared APIs, metadata standards, and such as fast-tracked permitting—can accelerate adoption. governance frameworks. Enforcing this mandate across Integrating SiPetruk reports into SLF issuance would address the current weak verification process. 118 BHUMI is an interactive geospatial platform developed by ATR/BPN to disseminate structured spatial data. https://bhumi.atrbpn.go.id/ RESILIENT FOUNDATIONS, GREEN FUTURES 61 SPATIAL DATA SOURCES SECTORAL GEO-DATABASES LOCATION ANALYSIS PERMITTING DISASTER RISK • Earthquake & fault lines • Topography, i.e., slope & elevation, landslide National Disaster susceptibility Risk Agency Database • Flood riskv( uvial, pluvial, (InaRISK) coastal, ash ood) • Thermal risk, i.e., land surface temp, UHI index • Soil conditions • Others HOUSING CONSIDERATIONS • Existing a ordable housing stock Ministry of Housing & • Developer database Settlement or Ministry of Public Works • Housing need projections • Housing qualitative & quantitative backlog target SETTLEMENT CONSIDERATIONS • Basic infrastructure, i.e., road, water pipe, electricity, etc. Local Government • Vital services, i.e., re station, hospital, school, GIS portal etc. Housing & Settlement 1. Land Use Permit (KRK) Location Suitability 2. Construction Permit • Slum identi cation Composite Map through (PBG) multi-criteria spatial LAND & PLANNING analysis CONSIDERATIONS • Land use & zoning Land Use & Zoning • Building intensity & development parameters Database • Land ownership & current Land Registry System utilization Ministry of Land • Land availability Management • Land price OTHER CONSIDERATIONS FIGURE 30. SCHEMATIC OF DATA-DRIVEN AND RISK-INFORMED LOCATION CHOICE FOR HOUSING AND SETTLEMENT DEVELOPMENT 62 Strengthen local government capacity to oversee construction transportation-related emissions; and (iv) a standardized quality. City-level Housing Departments must be trained to carbon savings calculator that quantifies emissions manage SiPetruk and issue SLFs effectively. Local agencies reductions from both construction practices and locational need better knowledge of construction risks and technical efficiencies. Strengthening BGH along these dimensions will tools to reduce dependency on national ministries. enhance its credibility, increase adoption, and position it as Coordination among land, environment, housing, and the national benchmark for sustainable affordable housing. permitting offices should be formalized through standard Ensure implementation is practical and developer friendly. workflows and hands-on implementation support. To support wide adoption, BGH must be cost-effective, 4. Strengthen the BGH Certification System into a easy to use, and capable of auditing hundreds of thousands Scalable,Integrated Framework of units annually. This will require regulatory reform, Transform BGH into a comprehensive and scalable particularly of Regulation 21/2021, to accommodate certification tool. To align with international best practices diverse housing types and streamline certification. and effectively drive green and resilient housing at scale, Use the KPR Subsidi program as a pilot for integrated the BGH certification system must be transformed into resilience and green standards. This program’s poor a comprehensive and robust tool. This requires the construction and location performance make it ideal for integration of four essential components: (i) enforceable piloting strengthened BGH criteria. Lessons from this minimum green design standards encompassing energy pilot can be used to refine the BGH system, demonstrate and water efficiency, sustainable materials, and passive scalability, and pave the way for nationwide mandates. cooling strategies; (ii) verified construction quality through Implement risk-informed planning and permitting through integration with SiPetruk and rigorous QAQC protocols integrated spatial data to ensure location suitability and to ensure performance matches design intent; (iii) location reduce household disaster exposure. suitability criteria that prioritize accessibility to jobs and services, support compact urban forms, and reduce RESILIENT FOUNDATIONS, GREEN FUTURES 63 A DETERMINE WHERE TO BUILD HOUSING DETERMINE WHAT AND HOW TO BUILD Disaster Risk Map Documents are prepared by builders supported by a licensed architect/ construction company. Alternatively, use ready-to-build prototypes. Land Use Housing Supply Administrative Technical docs & Zoning vs Demand Docs or resilient/ Compliance Database green building prototype Location Suitability Project Proposal PROJECT "GO/NO GO" DECISION Construction Permit (PBG) issuance Decisions by national/local government depend on the project scale. Submission through a digital platform. B C CONFIRM RESILIENT CONSTRUCTION STANDARDS CONFIRM GREEN CONSTRUCTION STANDARDS Resilient QAQC (building inspection) Green QAQC (building inspection) Certificate of Proper Function (SLF) Green Building Certificate (BGH) issuance issuance Performed by building inspectors, overseen by local government Performed by green building specialist (TABGH), overseen by (Penilik Bangunan) local government FIGURE 31. PROPOSED SCHEMATIC OF LINKING LOCATION ANALYSIS, TECHNICAL PROPOSAL, PBG, SLF, AND GREEN CERTIFICATION ISSUANCE FOR GOVERNMENT-LED HOUSING DEVELOPMENTS 64 4.2 ACTION H: ENABLE GREEN FINANCING AND CARBON CREDIT KEY RECOMMENDATIONS: 1. Tackle structural barriers to expand demand for 2. Unlock the housing sector’s carbon credit green housing finance by enabling developers potential through dedicated regulations and large- and homeowners through simplified processes, scale, high-impact energy efficiency interventions. awareness campaigns, and incentives. 4.2.1 Intervention Rationale Bank Indonesia has played an increasingly active role in advancing green finance, introducing a suite of macroprudential policies aimed at accelerating sustainable investment across sectors—including housing. See Box 3. BOX 3. Central Bank Incentives119 Bank Indonesia has introduced a set of macroprudential priority sectors may receive reserve requirement reductions. policies to accelerate green financing in the housing Loans for environmentally sustainable projects—such as sector, signaling its deepening commitment to sustainable green housing—are eligible for up to a 0.5% reduction. Banks development. providing affordable housing loans can receive up to an additional 1.1% reduction. Banks that exceed the 30% RPIM a) Macroprudential Inclusive Financing Ratio (RPIM): threshold may qualify for a further 0.3% reduction if they The RPIM requires banks to allocate at least 30% of their meet additional criteria, such as over 5% lending growth and a total lending to inclusive sectors, including housing. Banks sectoral market share above 2%. may fulfill this obligation through direct lending or inclusive securities, such as green bonds tied to sustainable housing. c) Green Construction in LTV/FTV Ratios: By classifying housing within the inclusive sector, the RPIM Bank Indonesia has set the maximum Loan-to-Value (LTV) and expands financing for low-income borrowers and encourages Financing-to-Value (FTV) ratios at 100% for green property banks to pursue green housing finance opportunities. loans, enabling full financing without down payments. This policy lowers upfront barriers for homebuyers and aims to b) Macroprudential Liquidity Incentive Policy (KLM): stimulate greater demand for sustainable housing solutions. Under KLM, banks that meet specific lending thresholds to 119 Bank Indonesia Regulation No. 23/13/PBI/ 2021 on Macroprudentional Inclusive Financing Ratio for Conventional Commercial Banks, Conventional Shariah Banks, and Shariah Business Units; Bank Indonesia Regulation No. 11 of 2023 on Macroprudential Liquidity Incentive Policy; Bank Indonesia Regulation No. 23/2/PBI/2021 on the Third Revision of BI Regulation No. 20/8/PBI/2018 on Loan to Value Ratio for Property Loans/ Financing and Down Payment for Auto Loans/ Financing; BI Board of Governors Regulation No. 24/ 6 /PADG/2022 on Implementation of Macroprudentional Inclusive Financing Ratio for Conventional Commercial Banks, Conventional Shariah Banks, and Shariah Business Units; BI Board of Governors Regulation No. 7 of 2025 on the Third Revision to the Board of Governors Regulation No. 11 of 2023 on Implementation of Macroprudential Liquidity Incentive Policy; BI Board of Governors Regulation No. 24/16/PADG/2022 on the Forth Revision on BI Board of Governors Regulation No. 21/25/PADG/2019 on Loan to Value Ratio for Property Loans/ Financing and Down Payment for Auto Loans/ Financing RESILIENT FOUNDATIONS, GREEN FUTURES 65 Green housing finance in Indonesia is beginning to show Mandiri’s green lending totaled just IDR 587 billion, or 3% traction in the high-income segment, particularly for larger of its total mortgage disbursement120. apartments and homes, where demand for sustainable In contrast, green financing for the affordable housing sector features is rising. Banks such as BRI, BNI, BCA, and is virtually non-existent. Despite various policy efforts and Mandiri have expanded their green finance portfolios pilot programs, the ability of low-income households to since 2021, offering preferential mortgage rates between access or afford green housing remains severely constrained. 2.6% and 5.6% for green-certified developments. In the Consumer awareness of green benefits is low, and even first half of 2024, green housing loans grew by over 200% small cost premiums are seen as prohibitive. On the supply year-on-year, largely driven by rising interest in units side, developers lack both the incentives and technical sized between 22 and 70 square meters. These products, capacity to build green within current housing price caps. however, are primarily geared toward middle- to high- For instance, BTN—the largest mortgage lender—does not income consumers, and remain a marginal component of offer a formal green mortgage product and instead launched total bank lending portfolios—accounting for less than 1% a “low carbon emission” program in 2024 targeting 1,000 of outstanding loans. For example, as of Q1 2024, only 8% units, which meet only basic eco-friendly criteria and are of BCA’s mortgage disbursements qualified as green, while not formally certified. 250 % %, yoy 250 200 200 150 150 100 100 50 50 0 0 -50 -50 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 6 7 8 9 10 11 12 1 2 3 4 5 2021 2021 2021 2021 Shophouses Flats Type > 70 Flats Type < 21 Flats Type 22-70 Total Housing Loans Growth (rhs) House Type > 70 House Type < 21 House Type 22-70 FIGURE 32. GREEN HOUSING LOANS GROW TH BY TYPE (SOURCE: BI, 2024) 120 Based on each bank’s Quarterly Analyst Presentations and Annual Sustainability Reports. 121 This cost increase is in comparison to existing sub-standard construction practices. Due to lack of quality enforcement and to stay within the KPR Subsidi price cap while maintaining profitability, developers tend to cut corners in construction quality. 66 Efforts to introduce green financing into the affordable billion—highlighting the market’s potential when policy segment, such as the Government’s pilot under the Green clarity and incentives are aligned.123 Affordable Housing Program (IGAHP), have faced But for low-income green housing, current carbon prices significant barriers. The program offers construction are too low to recover costs. Based on South Pole analysis, subsidies of up to 20% for self-built homes and 5% for adding rooftop solar or energy-efficient appliances across developer-led housing, contingent on meeting green and 433,900 homes would cost USD 38–130 million. However, resilient standards. However, early implementation of the projected carbon credit revenues over 10 years are only USD pilot has been slow. Operational challenges, including a 4–7.5 million—insufficient to justify green investments. The five-month setup period, weak facilitation, limited bank absence of residential-sector carbon mandates, combined participation, and complex eligibility requirements, have with low voluntary market prices (USD 3–7.8/tCO2e), constrained progress. Developers engaged in the pilot also make this an unsustainable path for now.124 reported that meeting resilient standards could increase costs by 8–40% (excluding green features), far beyond what is viable under current subsidy frameworks.121 These 4.2.2 Intervention approaches findings underscore the urgent need for stronger, better- 1. Address structural and knowledge barriers to shift targeted incentives and regulatory reforms to enable green market preferences towards green and resilient affordable housing at scale. housing. These challenges underscore the need to align Bank To scale green financing for the affordable housing sector, Indonesia’s green finance policies more closely with structural and knowledge barriers must be addressed affordable housing realities. Strengthened coordination across the entire ecosystem. Despite government incentives, with sectoral ministries, enhanced incentives for financial uptake remains low due to limited awareness, complex institutions to extend green credit to low-income segments, certification systems, and weak technical capacity among and simplified compliance frameworks for developers could developers and homeowners. Tackling these gaps is essential help translate macro-level policy ambition into real market to expand demand and adoption of green-resilient housing. uptake. Without such reforms, green finance will remain Public awareness campaigns are critical to shift perceptions out of reach for those who need it most. and build demand. Mass media, social platforms, and Carbon finance is not yet a viable solution to close the community workshops should highlight the economic, green housing financing gap. Indonesia’s residential sector safety, and environmental benefits of green housing, while is excluded from current carbon credit frameworks under dispelling misconceptions around cost and complexity. Presidential Regulation No. 98 of 2021. While other sectors Targeted messaging should reach homeowners, developers, like energy have advanced through carbon trading and offset financiers, and local governments. mandates, housing lacks pricing mechanisms, monitoring A centralized digital platform could streamline access to protocols, and eligibility for carbon transactions.122 green housing resources. The platform should consolidate In contrast, carbon trading in Indonesia’s energy sector key information: simplified green standards (e.g., BGH, is gaining momentum and demonstrates how strong EDGE, Greenship), housing prototypes, financing tools, a mandates drive participation. The launch of IDX Carbon database of certified housing, and application guidance— in 2023 and mandatory emissions trading for coal plants potentially linked to SiKumbang. led to 7.1 million tons of CO2 traded—worth ~IDR 84 122 Presidential Regulation No. 98 of 2021 on Carbon Economic Value Implementation 123 Minister of Energy and Mineral Resources Regulation No. 16 of 2022, on Mechanisms of Carbon Economic Value for the Electricity Power Generator Subsector 124 Carbon Finance Opportunities in the Affordable Housing Sector in Indonesia, South Pole (2025) RESILIENT FOUNDATIONS, GREEN FUTURES 67 Structural resilience must be enforced alongside green 2. Activate carbon credit potential in the housing standards. Without strong quality control, particularly for sector by establishing dedicated regulation and self-built and retrofit homes, green investments risk being leveraging scalable high-impact interventions undermined. Compliance with structural codes should be a The housing sector’s carbon credit potential can be prerequisite for any green initiative. unlocked through regulation and high-impact, scalable Simplified green certification is needed for self-built interventions. The lack of housing-specific carbon credit homes. A streamlined system with basic checklists and pre- frameworks prevents the sector from participating in approved designs can help low-income households adopt carbon markets, despite its mitigation potential. green practices incrementally without navigating complex Establishing housing-specific carbon credit regulations or costly certification pathways. is a foundational step. New rules must define emissions A transitional “green label” system can enable retrofit baselines, approved methodologies, and verification projects to demonstrate progress. Given the tailored nature protocols tailored to housing typologies—enabling of retrofits, a tiered system would allow homeowners to trusted, trackable, and tradeable carbon credits. track progress toward full compliance, encouraging gradual Initial efforts should focus on higher-energy, non- adoption and early market recognition. subsidized housing segments. These homes offer greater Engaging large commercial banks and Government emission reduction potential due to their size and platforms is key to scaling green housing finance. appliance use. Policies could target air conditioner Partnering with high-volume lenders (e.g., BTN, Mandiri, standards and construction practices in this segment to BRI) and deploying trained facilitators can broaden reach maximize impact. and improve compliance. National beneficiary databases Growing AC adoption in low-income housing presents and informal sector groups can streamline outreach an emerging opportunity. With 30% of low-income and selection. households using ACs—and more expected as prices Financial and technical incentives are essential to drive fall—there’s potential to combine high-efficiency ACs developer participation. Until green certification becomes with passive cooling to cut emissions. However, to qualify mandatory, transitional support—through subsidies, for carbon credit monetization, interventions must be branding benefits, or regulatory flexibility—is needed to deployed at scale. offset higher costs and encourage market entry. 68 05 Conclusion RESILIENT FOUNDATIONS, GREEN FUTURES 69 Indonesia's transition to climate-resilient, low-carbon Success will depend on a sequenced and system-oriented housing is both a critical necessity and a major approach. First, resilience must be prioritized, ensuring opportunity. This roadmap highlights that resilience must that all homes meet minimum safety standards to withstand come first—protecting vulnerable households from heat, climate and geophysical hazards. Only then can green floods, and earthquakes—while laying the foundation measures—passive cooling, energy-efficient appliances, for broader climate mitigation through green materials, low-carbon materials, rooftop solar—be layered on energy efficiency, and renewable energy. By integrating to maximize mitigation and affordability benefits. The risk-informed planning, scalable prototypes, robust roadmap’s dual focus on adaptation and mitigation quality control, and innovative financing, Indonesia recognizes the lived reality of low-income households: can mainstream green affordable housing across its resilience is foundational, while decarbonization must be programs. With strong government leadership, cross-sector practical and progressive. collaboration, and community participation, the housing Institutional integration is critical. Fragmented mandates sector can be a powerful driver of inclusive, sustainable and siloed systems currently hinder coordinated action. urban development. Reforming permitting and certification systems, scaling the Indonesia stands at a pivotal moment in its journey toward BGH green building standard, and operationalizing tools climate-resilient and low-carbon development. The housing like SiPetruk and SiKumbang will be key to ensuring quality sector, particularly the affordable housing segment, offers a and compliance. Capacity-building for local governments transformative opportunity to address the dual imperatives and streamlined monitoring frameworks are equally vital. of social inclusion and environmental sustainability. As this Green finance must be unlocked for all. Bank Indonesia’s roadmap outlines, achieving a future where all Indonesians macroprudential policies have laid the groundwork, but are sheltered from climate hazards while contributing greater alignment with affordable housing realities is to climate mitigation is both technically feasible and needed. Incentives must be extended to developers serving economically prudent. the low-income segment, and financing tools simplified to The climate and disaster risks facing Indonesia—extreme match the needs of informal and self-building households. heat, floods, and earthquakes—are intensifying, with While carbon credit remains a longer-term opportunity, disproportionate impacts on the poorest and most near-term scale can be achieved through targeted subsidies, vulnerable. At the same time, the country’s ambitious green mortgages, and rooftop solar rental models. housing targets, including President Prabowo’s Three Above all, green and resilient housing must be inclusive. Million Homes Program and the net-zero housing vision Community engagement, participatory design, and tailored under IGAHP, demand a new paradigm in policy, finance, solutions will ensure that climate-responsive housing not and implementation. This roadmap demonstrates that only protects but empowers Indonesia’s urban poor. By resilient and green affordable housing is not a luxury, it is integrating green and resilient principles across housing a necessity. design, location, regulation, and finance, Indonesia can redefine its urban future—building not just houses, but the foundations for a safer, healthier, and more equitable society. 70 5.1 SUMMARY OF ACTIONS AND KEY RECOMMENDATIONS 5.1.1 Climate Adaptation Recommendations Objective: Embed resilience to climate shocks, including flooding, earthquakes, and heat stress, into housing design, construction, and policy to safeguard lives, assets, and public investments. ACTIONS STRATEGIC RECOMMENDATIONS RESPONSIBLE STAKEHOLDERS125 Scale up passive cooling interventions in Government housing ACTION A programs such as BSPS to protect vulnerable families against MoHS Combat extreme heat. Thermal Stress with Gradually integrate passive cooling design into all MoHS Passive Government programs to reduce energy demand and build the MPW (DG Cipta Karya) Cooling foundation for energy-efficient housing. Design Socialize passive cooling interventions through local MoHS government, NGO’s and communities to keep low-income MPW (DG Cipta Karya), communities safe. Local Government ACTION B Accelerate the implementation of earthquake-resilient simple MoHS, MPW(DG Cipta Promote building prototypes and earthquake-informed PBG and SLF Karya, DG Bina Konstruksi), Resilient issuance, especially for Government-led housing program. Local Government Housing Design and Establish, integrate and monitor earthquake-resilient housing MoHS Construction retrofit guidelines in Government housing programs. MPW (DG Cipta Karya) to Withstand Prepare guidelines to accommodate household incremental MoHS Flood & design and construction modification by occupants. MPW (DG Cipta Karya) Earthquake Invest in flood-resilient housing research and flood-resilient MoHS MPW (DG Cipta Karya) building standard. BNPB Action C Embed disaster risk-responsive site planning into housing and MoHS, MPW, Bappeda, Risk-Informed settlement design. Local Government Integrated Implement neighborhood-scale design interventions to reduce MPW, Bappenas/ Housing Bappeda, BNPB, vulnerability to earthquakes, flooding, and thermal stress. Local Government and Slum Settlement Integrate physical interventions with community engagement Local Government Upgrading and public awareness campaign. NGO’s 125 Previously, the mandate for building and housing construction standardization was held by the DG of Cipta Karya under the Ministry of Public Works and Housing (MPWH), while construction quality training and monitoring fell under the DG of Bina Konstruksi. Under President Prabowo’s administration, MPWH has been split into two separate ministries: the Ministry of Public Works (MPW) and the Ministry of Housing and Settlements (MoHS). With this change, MoHS are responsible for construction standards, training, and monitoring for housing, however, they are required to coordinate with DG of Cipta Karya and DG of Bina Konstruksi (under MPW) who are responsible for construction standards, training, and monitoring for buildings in general. Meanwhile, the mandate for BGH (including for housing) still lies under the DG of Cipta Karya. RESILIENT FOUNDATIONS, GREEN FUTURES 71 5.1.2 Climate Mitigation Recommendations Objective: Build low-carbon, durable, and energy-efficient housing to reduce emissions while strengthening resilience to long-term energy and environmental shocks. ACTIONS STRATEGIC RECOMMENDATIONS RESPONSIBLE STAKEHOLDERS Prioritize low-embodied energy materials and implement MoHS ACTION D. passive design principles at the design and construction stage. Cut Operational Revise the SNI standards for household electrical appliances MoHS Energy and to incorporate energy efficiency requirements and formalize BSN-SNI Material- the mandatory use of SNI-certified home appliances in the MPW (DG Cipta Karya) Based green building certification regulation. Emissions Formalize green housing prototypes and guidelines for simple non-engineered housing under the authority of the MoHS Government body overseeing construction MPW (DG Cipta Karya) ACTION E. Adopt roof rental business models for RSPV utilization on public MoHS, MEMR, Explore buildings, including large public housing (rusunawa/rusunami). PT PLN, PT PLN Icon Plus opportunities Modify low-income housing design in Government housing MoHS to integrate program to meet RSPV adoption technical criteria MPW (DG Cipta Karya) Rooftop Solar Photo-Voltaic Pilot RSPV for Government low-income housing design, MoHS, MEMR, PT Panel especially for areas beyond Java-Bali grid PLN, PT PLN Icon Plus, Local Government Redesign Government-subsidized housing typologies to MoHS prioritize mid- to high-density formats that reduce land ATR/BPN consumption and urban sprawl. MoHS ACTION F. Promote compact urban forms and integrated sustainable Ministry of Transportation, Advance mobility through TOD. ATR/BPN, BAPPENAS, Sustainability CMIRD, Transit operators Through Invest in communal and district-level infrastructure MoHS, MEMR, PT PLN, Neighborhood and renewable energy systems to achieve scale-efficient PT PLN Icon Plus and City-Scale emissions reduction. Systems Incorporate green and blue infrastructure at the MoHS neighborhood level to sequester carbon, reduce urban heat, MoEF and enhance water resilience. Bappeda 72 5.1.3 Cross Cutting Recommendations ACTIONS STRATEGIC RECOMMENDATIONS RESPONSIBLE STAKEHOLDERS Establish integrated multi-hazard design prototypes and MoHS, ACTION G. guidelines to address seismic, flood, and thermal stress, and MPW (DG Cipta Karya) Build resilient accommodating universal accessibility requirements. and green Implement risk-informed planning and permitting through MoHS, BNPB, ATR/BPN, housing integrated spatial data to ensure location suitability and Bappenas, MoHA, BP construction reduce household disaster exposure. Tapera, Local Government design, permitting, Enforce housing construction quality through a robust MoHS, BP Tapera, monitoring QAQC system with the use of digital technologies and Local Government and cross-agency coordination. certification systems Strengthen BGH certification system into a scalable and MoHS, comprehensive assessment framework that aligns with MPW (DG Cipta Karya) international best practices. Tackle structural barriers to expand demand for green MoHS, MPW (DG Cipta housing finance by enabling developers and homeowners Karya), MoF, BI, OJK, ACTION H. through simplified processes, awareness campaigns, BP Tapera Enable green and incentives. financing Unlock the housing sector’s carbon credit potential through MoHS, MoEF, MoF, dedicated regulations and large-scale, high-impact energy BI, OJK efficiency interventions. RESILIENT FOUNDATIONS, GREEN FUTURES 73 05 Annexes 74 ANNEX 1: THERMAL RESILIENCE STUDY FOR LOW-INCOME HOUSING This study evaluates four passive cooling scenarios to Three key aspects of comfort were measured: thermal identify the most effective climate-adaptive strategies for comfort, air quality comfort, and perceived comfort. the design and construction of low-income housing. The Thermal comfort was assessed through indoor temperature, research took place in Desa Sooko and Desa Pedagangan, humidity, and air velocity. Air quality comfort was measured located in Kecamatan Wringinanom, Kabupaten Gresik— using particulate matter concentrations (PM 2.5 and PM approximately 30 kilometers from Surabaya. The study 10), while perceived comfort was determined through aimed to assess the indoor comfort performance and residents' feedback on their experience and the absence of affordability of different passive cooling designs for low- symptoms typically associated with sick building syndrome. income households. Using 40 houses built under the H4H In addition to measuring indoor comfort parameters, this project which are designed to resemble the BSPS housing, study also included outdoor microclimate monitoring to the study evaluated both environmental conditions and provide context and support accurate interpretation of residents' comfort perceptions. the data. All homes adhered to standard BSPS program specifications, Data Collection Method averaging 30 to 40 m² in size, constructed with basic The field survey was conducted over a three-month period, materials, and costing approximately IDR 42 million from November 22, 2024 to February 25, 2025. Each (US$ 2550) to build. The participating households had a house was monitored continuously for 36 hours during maximum monthly income of IDR 4 million (US$ 250), non-rainy days to ensure consistent data collection. representing the economic conditions commonly faced by The tools used to measure the quantitative data include: low-income families in Indonesia and aligning with the • Outdoor: (1) Automatic Weather Station, (2) beneficiary eligibility criteria of the BSPS program. Temperature and Relative Humidity Sensor + Air To ensure consistency in environmental conditions, all Quality Meter selected units are located within a similar microclimate • Indoor: (1) Temperature and Relative Humidity Sensor zone, minimizing variation due to uncontrolled outdoor + Air Quality Meter, (2) Anemometer to measure air variables. To maximize the relevance of passive design velocity, and (3) Thermocouple to measure surface strategies, additional site criteria were applied: houses temperature must be freestanding (i.e., not physically attached to neighboring buildings), sites must feature low to medium The qualitative data was collected through three vegetation density, avoiding areas such as dense forests, questionnaires and observation forms. to maintain comparable microclimatic conditions.To test Data Analysis Method the effectiveness of different cooling strategies, the 40 The thermal performance of each intervention houses were divided into five groups of eight units each. was measured against three parameters: The first group served as the baseline. Four passive design interventions (Reflective roof paint, Cross-ventilation, 1. a. Temperature and humidity stability Aluminum foil roof insulation, Ceiling with gable (Amplitude = Value max – Value min) ventilation) were tested against this baseline model. These b. Control performance houses were equipped with large roof overhangs and front (ΔT and ΔRH = the difference between outdoor terraces, providing some level of shading. and indoor measurements) c. Thermal lag (Time delay of out-in peaks in temperature and humidity) RESILIENT FOUNDATIONS, GREEN FUTURES 75 2. The comparison of different interventions was calculated using a normalized metric Δ(ΔT) against Baseline (Model A) to account for different outdoor conditions. Δ(ΔT)X = ΔTX – ΔTbaseline Δ(ΔRH)X = ΔRHX – ΔRHbaseline 3. The correlation of human perceptions analyzed using regression. ANNEX 2: COMMONLY USED CONSTRUCTION MATERIALS IN HOUSING DEVELOPMENT 1. EXAMPLES OF LOW-CARBON CONSTRUCTION MATERIALS FOR SUSTAINABLE HOUSING RED BRICKS PRECAST SOLID DENSE AUTOCLAVED AERATED CONCRETE PANELS CONCRETE BLOCKS CONCRETE BLOCKS (AACB) 1,616 MJ/m 2 907 MJ/m 2 407 MJ/m 2 317 MJ/m 2 CELLULAR LIGHTWEIGHT CONCRETE BLOCKS 232 MJ/m 2 TABLE 3. EMBODIED ENERGY OF COMMON WALLS MATERIALS FROM THE HIGHEST TO LOWEST EMBODIED ENERGY (LEF T TO RIGHT, TOP TO BOT TOM) ) 126 126 EDGE Materials Reference Guide Version 2.1 (2018) https://intisumberbajasakti.com/ 76 STEEL (ZINC OR ALUMINUM SHEETS CLAY TILES CONCRETE ROOF TILES GALVANIZED IRON) 812 (TIMBER RAFTERS) 812 (TIMBER RAFTERS) 243 (TIMBER RAFTERS) 110 (TIMBER RAFTERS) - - - - 886 (TIMBER RAFTERS) 879 (TIMBER RAFTERS) 373 (TIMBER RAFTERS) 239 (TIMBER RAFTERS) MJ/m 2 MJ/m 2 MJ/m 2 MJ/m2 TABLE 4. EMBODIED ENERGY OF COMMON ROOF MATERIALS FROM THE HIGHEST TO LOWEST EMBODIED ENERGY (LEF T TO RIGHT, TOP TO BOT TOM) ANNEX 3: GOVERNMENT HOUSING PROTOTYPES Site Management External lighting with sensor +2 points NO. CRITERIA MAX ATTAINED POINTS POINTS 1. Site Management 8 3 Shading vegetation & consumable gardens 2. Private Green Open 9 8 Space 3. Carports 2 2 4. External Lightings 2 2 TOTAL 21 15 Green area 11.38% Albedo 0.58 Carport available and does not Concrete floor finishing and grey roofings take up public ROW RESILIENT FOUNDATIONS, GREEN FUTURES 77 Operational Energy Efficiency Standard-compliant Room depths are maximum lighting for LED no more than 2x lamps | +5 points window heights NO. CRITERIA MAX ATTAINED POINTS POINTS 1. Building Envelope 16 10 Shading 2. Air Conditioning System 15 15 window to 3. Lighting System 10 10 Wall ratio 9.9% 4. Electrical System 5 0 TOTAL 46 35 Designed for natural ventilation (no AC) Water Efficiency Water meter for pumps | +8 points NO. CRITERIA MAX ATTAINED POINTS POINTS 1. Water Sources 15 8 2. Water-Savings Fixtures 15 15 At least 50% of all water TOTAL 30 23 fixtures and toilets are water-saving | +12 points NO. WATER FIXTURES MAX INSTALLED AMOUNT OF AMOUNT OF WATER- CAPACITY CAPACITY WF INSTALLED SAVING FIXTURES 1. WC, Flush Tank 6 liter/flush 3/6 liter/minutes 1 0 2. Wall Faucet 8 liter/minutes 4,5 liter/minutes 2 2 Kitchen Faucet 9 liter/minutes 4,5 liter/minutes 1 0 TOTAL 4 2 PERCENTAGE OF WATER FIXTURES WITH WATER-SAVING FEATURES 50% 78 Indoor Air Quality Kitchen and Cross ventilation NO. CRITERIA MAX ATTAINED bathrooms have POINTS POINTS natural ventilations 1. Indoor Air Quality 13 13 2. Refrigerant Material 5 5 Control Operable window TOTAL 18 18 > 10% Waste Management NO. CRITERIA MAX ATTAINED POINTS POINTS 1. 3R (Reduce, Reuse, 8 0 Recycle) 2. 15 15 Waste management implementation TOTAL 23 15 Unorganic waste management system working with local community Individual-scale Composters | +11 points TABLE 5. PROTOTYPES INITIATED BY MOHS STILL IN DEVELOPMENT STAGE RESILIENT FOUNDATIONS, GREEN FUTURES 79 ANNEX 4: CONSTRUCTION QUALITY ISSUES DURING NAHP The NAHP was implemented by the Ministry of Public The assessment revealed significant shortcomings in Works and Housing (MPWH) between 2017 to 2023, with construction practices. In the BP2BT sample, only 16 funding and technical support from the World Bank. To percent of houses fully met the minimum structural safety inform the program’s implementation, the Government standards as defined by Ministerial Decree Kimpraswil No. conducted a baseline assessment to evaluate construction 403/2002 and Ministerial Regulation No. 5/2016. In the quality of two major housing initiatives: BP2BT, a developer- BSPS sample, compliance was even lower at just 11 percent. led down-payment assistance program for home ownership, To meet these minimum standards, all five critical structural through a sample of 76 projects covering 1,003 houses in components—foundation, plinth beam, columns, ring 2019; and BSPS, a self-help housing improvement program, beam, and roof truss—must be installed correctly, using with technical assistance from Build Change in 2018. The proper techniques and compliant dimensions. However, in goal of the NAHP was to expand access to affordable and BP2BT projects, 37 percent of homes were categorized as adequate housing for low-income households. partially safe, while 47 percent were classified as unsafe due to significant deviations from these standards. NAHP CONSTRUCTION QUALITY BASELINE ASSESSMENT FINDINGS BP2BT → Developer-built BSPS → Self-built/ self-retrofit only 16% meet minimum only 11% meet minimum construction standard[1] construction standard[2] STRUCTURAL INTEGRITY HEALTHY 11% 89% 37% 47% 47% 53% 16% 89% 11% Tidak Aman Mendekati Aman Aman Structural Component Healthy Component 36% Foundation 99% Lighting 91% Foundation 90% Lighting 41% Plinth Beam 91% Plinth Beam 35% Plinth Beam 89% Plinth Beam 22,4% Column 100% Toilet 38% Column 81% Toilet 26,3% Ring Beam 100% Clean Water 47% Ring Beam 85% Clean Water 43,4% Roof Truss 100% Electrity 93% Roof Truss 93% Electrity 95% 92% 92% 61% Location Safety Drainage Location Safety Drainage System Common deficiencies included substandard column for gable walls—heavy components that pose serious dimensions, poor mortar quality, inadequate steel bar sizing risks during earthquakes if not properly supported. Such and configuration, and the absence of essential structural deficiencies drastically increase the vulnerability of these elements such as ring beams and columns. A particularly houses to seismic events. alarming finding was the lack of structural reinforcement 80 SIMILAR CONSTRUCTION QUALITY ISSUES FOUND IN BP2BT & BSPS HOUSES BP2BT DEVELOPER- BUILT KEY ISSUES: 1. Column 2. Sloof 3. Ring Beam • Dimension 1. Column dimension below standard, low 1. Some houses had no ring beams and • Mortar quality mortar quality or columns • Number of steel bar 2. Diameter of steel bar is too small 2. No structural support for gable walls • Connection 3. Column only had 3 main rebars (standard is 4) with diameter below standard (2 projects in Lampung) In some cases, roof truss without wind tie and anchor BSPS SELF-BUILT 1. Column dimension below standard, 1. Low mortar quality low mortar quality 2. Gable is too heavy without 2. Distance between stirrup is too wide (>15 cm) adequate wall frame structure 3. No overlap steel bar connection between sloof-column and column-beam In response to these findings, the NAHP program developed at the local level and randomized audit by the project and implemented a Quality Assurance and Quality Control implementation unit and the World Bank at the central (QA/QC) tool aimed at improving construction oversight. level, ensuring the reliability of assessment results. This intervention led to substantial improvements in 4. Widespread training and socialization among structural compliance, with reported quality increasing stakeholders, enhancing skills and awareness among threefold in BP2BT projects and sevenfold in BSPS homes. facilitators, developers, and households—including The QAQC system succeeded due to four critical female-headed ones. components: During the pandemic, a virtual monitoring system helped 1. Evidence-based monitoring through different stages of remotely verify construction and guide assessment process. construction until completion; These elements enabled real improvements in construction integrity, setting a precedent for other housing programs. 2. A clear and easy-to-use checklist-based monitoring tool which required photo documentation of key Ensuring long-term quality demands sustained investments structural elements as evidence, enabling more in oversight and training. Future programs must focus on accurate assessment; robust institutional frameworks, skilled personnel, and ongoing capacity-building to avoid repeating past mistakes 3. Multi-level monitoring, involving construction and ensure consistent adherence to construction standards. assessment by facilitators or construction supervisors RESILIENT FOUNDATIONS, GREEN FUTURES 81 ANNEX 5: CLASSIFICATION OF CITY AND TOWN CHARACTERISTICS Indonesia’s urban growth is unfolding unevenly across where such interventions are most needed and where urban its six-tier city classification, as defined by Roberts et al. consolidation should be prioritized. (2019), revealing a growing spatial mismatch between 1. Tier 1: Multi-Districts Metro Core: Large metropolitan housing supply and actual population demand. While Tier areas with functional labor markets that cut across 1 to 3 cities—comprising major metropolitan cores and multiple kota/kab. e.g., DKI Jakarta, Bandung, dense single-district urban centers—continue to experience Semarang, Surabaya rapid population growth, they face significant constraints 2. Tier 2: Urban Periphery: Predominantly urban areas, to outward expansion due to limited land availability, non-core districts, e.g., Bodetabek, Cimahi, Gresik, infrastructure congestion, and rising environmental risks. Kendal, etc. Yet, government housing programs remain heavily skewed toward low-density, peri-urban, and rural areas (Tiers 4 3. Tier 3: Single-District Metro Core: Kota/kab with to 6), where land is more available, but demand is lower. populations ≥500,000 and high density but whose This spatial misalignment has resulted in sprawling, car- labor market mobility is confined internally e.g., dependent settlements that are slow to absorb urban Padang, Pekanbaru, Jambi, Palembang, etc. population pressures and environmentally unsustainable. 4. Tier 4: Rural Periphery: Predominantly rural areas, Without a decisive shift toward compact and integrated non-core districts, e.g., Kab. Semarang, Demak, urban development—particularly through the densification Blitar, etc. of Tiers 1, 2, and 3 cities—Indonesia risks locking itself into 5. Tier 5: Non-Metro Urban: Kota/kab that do not meet a pattern of inefficient land use, higher infrastructure costs, the criteria to be metropolitan area but within which and escalating carbon emissions. Densification strategies most of the population is urban, e.g., Kota Magelang, that co-locate affordable housing with transit, services, Kota Madiun, Pekalongan, etc. and jobs are urgently needed to reduce sprawl, safeguard 6. Tier 6: Non-Metro Rural: Kota/kab away from the environmental systems, and ensure urban areas remain metro areas in which most of the population is rural livable, inclusive, and climate resilient. The Roberts et al. e.g., Wonogiri, Brebes, Gunungkidul, etc. (2019) city typology offers a valuable lens to understand 82 ANNEX 6: GREEN RETROFIT AND DENSIFICATION STUDY IN SOUTH SUMATRA128 In 2022, supported by the City Climate Finance Gap Trust Through a pilot program encompassing three cities— Fund, the World Bank worked with the South Sumatra Palembang, Lubuklinggau, and Musi Rawas—new retrofit provincial and local governments to draft design plans designs were developed for 34 homes, ensuring compliance to retrofit, extend, densify and build more than 100 with green and livability standards. Whenever possible, climate-smart homes in three cities across the urban-rural economic space to support livelihoods is also added, continuum in South Sumatra. like small shops or rental rooms. This approach offers a scalable solution to improve housing stock without mass The retrofit and densification cases are focusing on the displacement. For densification, 19 homes across 3 cities urban area to address inadequate, unsafe homes and were studied for vertical densification. By building upward housing stocks shortage. In urban areas, homes are often — adding floors to existing structures or combining plots well-located but inadequate and unsafe. Common issues for larger developments — communities can accommodate include poor structure, heat-absorbing materials, limited population growth sustainably without consuming ventilation, and poor neighborhood livability. more land. A. RETROFIT B. DENSIFICATION C. SELF-CONSTRUCTION Common issues identi ed in 1. Rooms are dark with limited Developer-led natural ventilation housing is limited the low-income neighborhoods 2. Poor structure in rural area. in urban area are: Vacant land 3. Heat-absorbing materials for available. Well-located, yet walls & roof inadequate and unsafe 4. Limited or no green area homes 5. Poor neighborhood livability A. 34 HOMES IN 3 CITIES B. 19 HOMES IN 3 CITIES C. 47 HOMES IN MUSI RAWAS Retro t/ Green housing and neighborhood design Reconstruction to with 2 typology reach green/ housing adequacy standards, while adding economic space whenever Adding more units possible through vertical development on one BEFORE AFTER big land or land plots from several HH’s 128 https://www.worldbank.org/en/news/feature/2024/12/03/green-homes-resilient-cities-tackling-indonesia-housing-crisis RESILIENT FOUNDATIONS, GREEN FUTURES 83 1. RETROFIT ONLY for additional household income through micro-enterprise and rental earnings. This integrated approach supports The proposed green retrofit integrates a series of passive both climate adaptation and economic empowerment for design improvements aimed at enhancing thermal comfort vulnerable households. and energy efficiency in low-income housing. Key design modifications include (a) the introduction of an inner 3. DENSIFICATION courtyard for improved ventilation, (b) additional windows This scenario addresses both overcrowding and structural to enhance natural lighting and airflow, (c) expanded green inadequacies by introducing a densification design that open space with vegetation to reduce heat absorption, (d) optimizes land use while enhancing environmental quality. external shading on the front porch to block direct sunlight, By reconfiguring a 70 m² land parcel to accommodate and (e) the application of reflective paint on roofs and walls five residential units, this approach significantly increases to minimize heat gain. While these interventions entail an housing stock within the same footprint. Key interventions incremental construction cost increase of approximately include the addition of (a) green open space with vegetation 6 percent, they offer long-term economic benefits by to improve microclimate and outdoor comfort, (b) potentially reducing annual utility expenses by USD 30 per construction of one primary housing unit, (c) four rental household, making them a cost-effective step toward more units, and (d) a designated parking area. This approach sustainable and livable housing. offers a scalable solution to urban land constraints while 2. RETROFIT WITH ECONOMIC SPACE supporting rental income opportunities and improved living conditions. This retrofit scenario combines passive cooling strategies with small-scale income-generating features to improve Retrofitting homes with vegetation, improved ventilation, both the livability and financial resilience of low-income and energy-efficient materials can enhance resilience and housing. The design incorporates (a) enhanced ventilation reduce carbon emissions. Densifying neighborhoods by to improve indoor thermal comfort, (b) reflective paint on adding rental units to existing homes can create income roofs and walls to reduce heat absorption, and (c) spatial opportunities and expand housing availability. Constructing modifications to accommodate two retail units and one new homes with locally sourced materials and traditional rental room. These upgrades increase construction costs designs can stimulate economic growth. through tourism by approximately 7 percent but provide dual benefits: an while simultaneously enhancing climate resilience. estimated USD 15 in annual utility savings and the potential ANNEX 7: INSTITUTIONAL SILOS IN THE HOUSING SECTOR Indonesia’s housing, spatial planning, and disaster policy, spatial planning, and disaster risk reduction (DRR). risk management systems are marked by complex and This fragmentation extends to sub-national levels, where fragmented institutional arrangements, with overlapping local housing departments, BPBDs (local disaster agencies), mandates and siloed functions that hinder coordinated and and planning authorities often work in isolation. Policy climate-resilient development. levers and data systems reflect this disconnection: disaster risk agencies use InaRISK and DIBI, housing agencies rely At the national level, key actors—including MoHS, on HREIS and Sikumbang, while spatial data is managed Bappenas, ATR/BPN, MoEF, and BNPB—operate separately through GISTARU and SIMBG. independently, with limited integration across housing 84 These platforms lack interoperability, shared governance managed by different entities (DG Cipta Karya, DG Bina protocols, and synchronized data updates, undermining Konstruksi, and local governments respectively), with joint risk assessments and delaying coordinated responses. limited enforcement capacity and weak accountability— Additionally, while construction standards, training, particularly for verifying technical quality in low- and occupancy certification mechanisms exist, they are income housing. CLIMATE CHANGE HOUSING POLICY ADAPTATION & DISASTER RISK SPATIAL PLANNING REDUCTION(CCA/DRR) National actors MoHS, Bappenas, Bappenas, BNPB, MoEF Bappenas, ATR/BPN, ATR/BPN CMIRD Local Government, Local Government, Local Government Sub-national actors Dinas Perumahan BPBDs • Housing program • National Plan on • RPJMN Policy Levers Disaster Management • Subsidy • RTRWN (RIPB) • Incentive • RTRWP • National Action Plan on • Grants DRRR • RTRWK • Public housing • Provincial Disaster • RDTR Management Plan • Building Permit (PBG) • Local Disaster Management Plan Data & Information HREIS DIBI & InaRISK GISTARU system Sikumbang SIMBG RESILIENT FOUNDATIONS, GREEN FUTURES 85 ANNEX 8: CALCULATION OF GHG EMISSIONS REDUCTION South Pole, a climate impact consultancy, estimated GHG savings have been recalculated to reflect this actual volume. emission savings for KPR-subsidized homes based on an The table below presents the GHG emission savings using annual delivery of 433,900 units, covering both embodied both the original South Pole volume assumptions and the and operational emissions. 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