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Decarbonizing the Built Environment Policy Brief

Decarbonizing the Built Environment Through Heritage Policy Brief November 2026 A framework for policymakers to advance climate change mitigation through heritage- informed solutions

Title: Decarbonizing the Built Environment Through Heritage: Policy Brief Produced by: Built Buildings Lab, based on the Decarbonizing the Built Environment Through Heritage: The Complete Toolkit Project Contact Lori Ferriss Executive Director Built Buildings Lab Representative, CHN Built Environment Forum lori@builtbuildings.org Citation: Built Buildings Lab . Decarbonizing the Built Environment Through Heritage: Policy Brief. Built Buildings Lab, 2026. Copyright: Built Buildings Lab. The report is distributed under the Creative Commons CC BY-NC-ND 4.0 license

Policy Brief DECARBONIZING THE BUILT ENVIRONMENT THROUGH HERITAGEThe Decarbonizing the Built Environment Through Heritage: Policy Brief demonstrates how policymakers can: » Use existing and heritage buildings as decarbonization assets » Apply heritage knowledge to new development, drawing on proven, place-based approaches to building and adaptation » Advance multiple public priorities at once, linking decarbonization with housing, health, jobs, resilience, and resource conservation » Put these approaches into practice through five principles, integrating policy levers, real- world examples, and points of entry

1Policy BriefDECARBONIZING THE BUILT ENVIRONMENT THROUGH HERITAGE Decarbonizing the Built Environment Through Heritage Policy Brief Executive Summary The built environment interlinks the places where we live and work with patterns of materials use and waste, the quality of the air we breathe, human health and well-being, and cultural identity. Heritage-informed solutions—including building care and reuse, traditional low-carbon materials, salvage, local urban planning practices, and traditional knowledge—sit at the nexus of these issues. They can reduce whole-life carbon by tackling embodied and operational emissions while reducing waste and raw material consumption, improving air quality, strengthening climate resilience, and fostering human health and well- being. They can also lower utility bills, support affordable housing, and create local jobs and economic opportunities. At the same time, these approaches can strengthen social cohesion and cultural continuity, connecting climate action with community values and priorities and inspiring wider change. Heritage-informed decarbonization offers policy opportunities to accelerate emissions reductions in the built environment while supporting thriving communities. Buildings and construction account for 34% of CO2 emissions. Despite increased investment and coordination since the adoption of the Paris Agreement, the sector’s emissions have increased by 6.5% over roughly the last decade, remaining far off track to meet decarbonization targets.1 To date, policy responses have largely overlooked the technical and cultural solutions found in cultural heritage. Heritage-informed decarbonization mobilizes proven strategies, time-tested knowledge, and the existing building stock to offer complementary pathways that accelerate emissions reductions while delivering benefits to people and communities.

2Policy BriefDECARBONIZING THE BUILT ENVIRONMENT THROUGH HERITAGE Adapted from the Decarbonizing the Built Environment Through Heritage (DBTH) Toolkit, this brief helps decision makers integrate heritage-informed decarbonization into climate, building, land use, and heritage policy. It provides five principles, practical policy levers, and points of entry for implementing solutions within local contexts. Principles for Policy Action The five principles of heritage-informed decarbonization can help governments accelerate climate action in the built environment through strategies that create cultural, environmental, and economic benefits. Putting these principles into practice requires coordination across climate, building, land use, and heritage policies and the agencies responsible for them. Governments, at all scales, can use regulation, economic incentives, public investment, informational tools, and Learn from the Past Reuse First Engage Place Revalue Building Waste Make Policy Inclusive 1 2 3 4 5 Five Principles of Heritage-Informed Decarbonization Learn from the greatest living laboratory for climate adaptation—the existing built environment. Prioritize continued building (re)use and care. Implement place-based solutions to build, maintain, and live sustainably. Reframe building waste as a resource. Include heritage and Indigenous voices in climate policymaking. property-based mechanisms. Some contexts require new policies or policymaking processes; others can advance through cross-agency coordination and targeted changes to existing approaches. Scaling Heritage Solutions Climate solutions for the built environment already exist in the heritage places and practices of many communities. The policy challenge is to recognize, enable, adapt, and scale these solutions as viable decarbonization strategies. To do so, governments must mainstream heritage-informed decarbonization approaches across climate, building, and cultural policy rather than treating heritage as a standalone issue. By working across these sectors, policymakers can accelerate decarbonization while helping communities move toward a more just, resilient, and low- carbon future.

Case Study AGNES COLLEGE3 Introduction: Why building sector climate action needs heritage Climate solutions for the built environment already exist in heritage places and practices around the world, embodying knowledge developed through generations of building and living in response to local conditions. Heritage-informed decarbonization draws on this time-tested knowledge and the existing building stock as resources to reduce emissions while centering people at the heart of climate action. By connecting emissions reductions with community values and priorities, it can support community action, protect culture and heritage, and advance durable decarbonization. Co-Benefits of Heritage Heritage-informed decarbonization offers a broad range of co-benefits: outcomes that simultaneously improve environmental performance, strengthen communities, and support economic development, human health, and social cohesion. These co-benefits can strengthen the case for investment through tangible outcomes and shared goals across housing, health, economic development, and resilience. They can provide an entry point for communities to engage in climate policy by linking action to local priorities. Evaluating these benefits alongside emissions captures the full value of heritage-informed climate action. Barriers to Implementation Despite their potential, heritage-informed solutions are often overlooked in policy. Enabling wider adoption requires addressing both policy barriers and the cultural norms that shape how buildings are designed, used, and maintained, including: What is Heritage-Informed Decarbonization? Heritage-informed decarbonization applies the wisdom, practices, and places of the past to minimize greenhouse gas emissions from the built environment in the present and future. It reduces greenhouse gases while safeguarding and generating cultural value – the shared practices and identities that connect people to each other and their past. It includes materials, buildings, and places (tangible heritage) and traditions, knowledge, and practices passed from generation to generation (intangible heritage). Together, these contribute to climate outcomes while generating social, cultural, and economic co-benefits.

4Policy BriefDECARBONIZING THE BUILT ENVIRONMENT THROUGH HERITAGE » Fragmented policies across climate and environment, building and construction, land-use, and heritage agencies and organizations. » Policies that incentivize new construction over reuse, deliberately or unintentionally, through tax structures, building and energy codes, and land-use requirements. » Policies that address operational emissions from energy use in isolation from embodied emissions associated with materials impacts, rather than considering whole life carbon. » Building and construction investment and attention focused disproportionately on new construction and technology. » Cultural norms in many parts of the world that favor mechanical conditioning, industrialized design, a take-make-waste mindset, and passive approaches to maintenance and operations. » Gaps in quantitative assessment of the emissions-reduction potential of heritage- informed solutions. The Complete Toolkit This brief is adapted from the Decarbonizing the Built Environment Through Heritage (DBTH) Toolkit, a resource for policymakers, practitioners, advocates, and community leaders.2 The Toolkit provides key terms and framing, discussion of the five principles and associated policy levers, context prompts to engage with community, and fourteen detailed case studies of buildings, practices, programs, and policies. These resources provide further context for interpreting the policy agenda and considering its application in different geographic locations and at different scales of government. Access the Toolkit at www. builtbuildings.org/dbth-toolkit. Five overarching principles emerged from a global review of policies and practices as key to advancing heritage-informed decarbonization and delivering measurable emissions reductions. Each addresses a major built environment decarbonization challenge with reference to specific barriers, policy levers, expected outcomes, and examples. Integrating these approaches into policy can support more effective and inclusive implementation, enabling people to thrive rather than merely survive climate change. Action across the five principles requires a range of policy instruments. In many cases, existing policies can incorporate heritage through reframing or revision, or policy approaches can be adapted from other regions. In other cases, novel approaches to policy and policymaking may be needed to rapidly accelerate heritage-informed decarbonization. Advancing heritage-informed decarbonization in policy

Case Study AGNES COLLEGE5 Barriers to Policymaking Technical guidelines and government investment in building and climate technology often focus on new materials and approaches to the exclusion of heritage knowledge. Without an understanding of heritage technologies, materials, and buildings, decision makers may dismiss them as irrelevant and develop new approaches without learning from the past. Conversely, heritage guidelines can restrict new materials and technologies needed for climate adaptation and stewardship. Integrating heritage knowledge and values into technological innovation can help accelerate effective solutions. Policy Levers • Establish public heritage structures as living labs to understand the “how and why” of past design approaches, test new materials, demonstrate the integration of old and new, and translate lessons learned into public guidance. • Invest research and development funds in new climate technologies informed by historic materials and practices. • Support diagnostics, monitoring, simulation, and shared data to guide upgrades to existing buildings, verify emissions reductions, and assess future climate performance while safeguarding heritage values. • Develop guidelines for design, occupation, and maintenance that demonstrate how to activate the sustainable features of heritage buildings and places. Built heritage illustrates how people have responded to climate over millennia, providing a unique test bed for mitigation and adaptation. Understanding how buildings are designed and used—and how they perform over time—can inform innovation for a low-carbon, resilient, and just built environment. Heritage buildings also offer opportunities to test and responsibly integrate new materials and systems. New technologies can help evaluate the energy, environmental, and heritage impacts of climate upgrades, enabling approaches that leverage heritage strengths, prepare buildings for the future, and avoid maladaptation. POLICY PRINCIPLE 1 Learn from the greatest living laboratory for climate adaptation—the existing built environment.

6Policy BriefDECARBONIZING THE BUILT ENVIRONMENT THROUGH HERITAGE 6 • Fund technical assistance programs for building owners to optimize decarbonization and improve resilience while retaining cultural value. • Create opportunities to test and integrate technological innovations into heritage building requirements. What This Delivers Learning from how buildings have adapted and performed over time can guide investment in new technologies and effective adaptation for the future. Applying proven heritage-informed solutions alongside appropriate upgrades can help meet the urgency of decarbonization. The Heritage Council of Victoria’s Climate Action Plan (Australia) combines protection from climate impacts with recognition of heritage conservation’s contribution to decarbonization. It embeds climate awareness in Council processes, promotes innovative adaptation, and supports research and guidance for heritage owners and managers.3 The MENA Guide to Heritage-Centric Approaches by the Cities Alliance highlights traditional knowledge and design approaches throughout the Middle East and North Africa (MENA) region that preserve water resources, minimize urban heat islands, and enhance air circulation.4 The Historic Building Energy Retrofit Atlas (HiBERatlas) and HiBER Tool, developed through projects coordinated by EURAC Research (Italy), support energy upgrades that respect heritage values. The atlas documents European retrofit case studies; the tool guides users toward suitable measures based on their building’s characteristics, with information on benefits, drawbacks, and performance.5 The Sustainable Traditional Buildings Alliance’s Guidance Wheel (UK) supports responsible energy retrofits that balance environmental and heritage outcomes by showing how different interventions interact, and highlighting their benefits and risks.6 The BEACON project, coordinated by the National Research Council’s Institute of Heritage Science (Italy), is developing a playbook to guide energy and environmental improvements to historic buildings, using building performance simulation while preserving heritage value.7 Masons Ink (Bengaluru, India), an architecture and design firm, trains women in low-carbon construction with earth and bamboo, and brings together all-women mason teams for its projects. By connecting hands-on training with traditional craft knowledge and local materials, the initiatives challenge biases against both women in construction and earthen building practices, while also supporting local livelihoods and economic development.8 Examples, Tools, and Resources

Case Study AGNES COLLEGE7 Barriers to Policymaking Building reuse and upgrades can be more complex and varied than standardized new construction. Design teams, owners, and builders accustomed to new construction may lack the knowledge needed for these projects. Prescriptive policy requirements and financial incentives designed for new construction can inadvertently discourage reuse, while climate policies often overlook maintenance and minor renovations. Historic buildings may also require tailored regulatory processes and support for the time and cost of diagnostic assessments to reduce emissions while safeguarding heritage values. Policy Levers • Implement reuse-first zoning, urban planning, and land use policies to incentivize existing building projects over demolition and new construction. • Mandate whole life carbon reporting and reduction for all buildings using methods that credit the avoided emissions of reuse. • Offer flexible compliance pathways—not exemptions—for existing and historic buildings to comply with energy and emissions requirements. • Align decarbonization and heritage financial incentives to support solutions that preserve heritage value while reducing emissions, including through maintenance and minor upgrades. • Penalize prolonged vacancy to support building maintenance, return underused space to housing and other community There is no pathway to a livable climate without leveraging existing buildings. Heritage- informed approaches to building (re)use preserve sense of place while addressing both embodied and operational emissions. Reuse avoids upfront emissions associated with new construction, with a reported 50–75% reduction in embodied emissions compared with new construction.9 Energy retrofits, electrification, and restoration of passive comfort strategies can reduce ongoing operational emissions. Together, reuse and operational upgrades reduce emissions in the near term and over a building’s life, whereas operational savings from a new building may take decades to offset construction emissions. POLICY PRINCIPLE 2 Prioritize continued building (re)use and care.

8Policy BriefDECARBONIZING THE BUILT ENVIRONMENT THROUGH HERITAGE 8 needs, and promote economic growth and urban vitality. • Fund training and technical assistance for building owners, practitioners, and builders to navigate heritage-sensitive building reuse, maintenance, and energy upgrades. What This Delivers Reusing and maintaining existing buildings can align environmental, economic, and social outcomes, meeting housing and community needs, reducing emissions, supporting local economies, improving air quality, preserving cultural value, and limiting raw material use. The City of Westminster’s Retrofit First Policy (London, UK) requires project proponents to 1) study opportunities for reuse, 2) develop a circularity statement, and 3) conduct life-cycle assessments for all renovation and new construction projects.10 New York State’s Historic Rehabilitation Tax Credits (USA) can be used for energy efficiency improvements and on-site renewable energy installations, showing how a common U.S. preservation incentive can be aligned more directly with decarbonization goals.11 The City of Amsterdam (Netherlands) passed the Empty Vacancy Act to address a growing shortage of affordable housing in the city by requiring building owners to report building vacancies to local agencies or face financial penalties.12 The City of Los Angeles Adaptive Reuse Ordinance (USA) is a citywide policy that provides development and approvals incentives for reuse over replacement to generate affordable housing while creating a low-carbon development pathway for underutilized buildings.13 The Carbon Avoided Retrofit Estimator (CARE Tool) is a free online resource to compare the carbon footprint of renovating and upgrading an existing building versus demolishing and replacing it with new construction.14 Saving Embodied Carbon Through Strengthening Existing Housing by nonprofit Build Change demonstrates that upgrading existing homes for disaster resilience saves approximately two- thirds of embodied carbon compared with new construction.15 ICOMOS’s report “Implementation of the European Energy Performance of Buildings Directive” (EU) guides coordinated policy implementation that recognizes broader heritage value and integrates maintenance, sensitive retrofits, better data, and interdisciplinary expertise to improve energy performance while safeguarding historic assets.16 Ireland’s Office of Public Works “Approaches to Improving the Energy Performance of Heritage Properties in State Care” provides a replicable method for assessing heritage buildings and developing upgrades that balance heritage values with energy efficiency.17 Examples, Tools, and Resources

Case Study AGNES COLLEGE9 Barriers to Policymaking In many parts of the world, policies shaped over time by industrialized construction have displaced place-responsive practices with standardized approaches. These policies based in new construction can exclude traditional materials such as timber, masonry, earth, and other bio-based materials, while the cost and scale of compliance testing can further limit their commercial use. Heating, cooling, and ventilation standards designed around energy-intensive mechanical systems can make it difficult for passive approaches based on human comfort and behavior to demonstrate compliance. Gaps in knowledge and practical experience among officials, designers, owners, and builders also hinder the use of local materials and climate-responsive practices. Policy Levers • Include local, traditional building materials such as earth, timber, and thatch in building codes to enable safe and effective use, and train building officials to support implementation. • Fund demonstration projects using local, traditional building materials to validate performance, inform codes and standards, support marketplace growth, and build confidence in their use. • Provide performance-based and outcome- based compliance pathways for building heating, cooling, and ventilation standards that prioritize occupant comfort, health, well-being, and usability. Heritage offers scientifically supported lessons in low- carbon design, construction, maintenance, and use, from local, bio-based materials to context- specific passive comfort strategies. It also fosters a culture of care that sustains local practices across generations. As the building sector has industrialized, place- based design and construction practices have increasingly given way to standardized approaches, weakening relationships between buildings, natural environments, landscapes, and cultures and contributing to the loss of knowledge and craft. POLICY PRINCIPLE 3 Implement local solutions to build, maintain, and live sustainably.

10Policy BriefDECARBONIZING THE BUILT ENVIRONMENT THROUGH HERITAGE10 • Fund education in passive design techniques for building officials, owners, and designers, and help owners operate their buildings effectively for their needs. • Support workforce development in traditional trades and craft skills to strengthen or re-establish local know-how of low-carbon approaches. What This Delivers Place-based approaches found in heritage can support decarbonization and livability of existing buildings as well as new construction at scale—reducing emissions and operating costs, increasing durability and maintainability, and strengthening local capacity. The Indigenous Climate Action Toolkit (Canada), developed by Indigenous Climate Action, builds capacity for Indigenous communities to identify and implement place-based climate strategies and solutions.18 New Mexico’s Earthen Building Materials Code (USA), issued by the Regulation and Licensing Department’s Construction Industries Division, establishes minimum standards for earthen bearing walls in one- and two-family dwellings.19 The Hikma Community Complex (Dandaji, Niger), designed by Mariam Issoufou Architects and Studio Chahar, combines heritage preservation and reuse with new construction using local, low-carbon materials to meet community needs.20 The Relevancy Guidebook: How We Can Transform the Future of Preservation (Illinois, USA), published by Landmarks Illinois, connects built heritage with climate issues and urges preservation practitioners to contribute to climate action and decarbonization.21 The FuturHist project (Europe), developed by a European consortium coordinated by Eurac Research, develops scalable, responsible retrofit strategies for common historic building types, with resources for practitioners, policymakers, building managers, and residents.22 The National University of Singapore’s Equatorial School of Architecture is a net-positive energy renovation of a 1970s-era building that took inspiration from tropical vernacular architecture to develop high-performance hybrid thermal comfort and ventilation systems. The building serves as a “living lab” for the university and the public and has provided a model for the updated Singapore Building Code.23 Examples, Tools, and Resources

Case Study AGNES COLLEGE11 Barriers to Policymaking The global industrialized construction sector has evolved around a take-make-waste economy over several centuries. Implementing circularity requires overcoming technical and logistical barriers, including shortages of skilled labor, storage costs, quality-control needs, and unpredictable material supply. These interconnected challenges require coordinated public and private action. Additionally, fragmented responsibilities across waste management, historic preservation, building regulations, and code development can hinder deconstruction, salvage, and materials reuse. Policy Levers • Strengthen demolition reviews to require assessment of building retention, repair, and reuse before demolition is approved. • Prioritize deconstruction over demolition when building-scale reuse is not viable through mechanisms like deconstruction ordinances, material recovery requirements, and increased landfill fees. • Allow reused materials to count toward embodied carbon reduction requirements. • Enable the reuse of salvaged materials without downcycling through codes and material standards. • Support workforce training and certification for contractors and technical guidance and training for owners, designers, and building officials in repair, deconstruction, and materials reuse. Globally, the construction industry generates 30–40% of all solid waste while consuming 40–50% of raw materials.24 From pre- industrial practices and present- day communities that have never adopted a take-make-waste mindset, heritage construction and maintenance demonstrate circular approaches that avoid waste and keep materials in use longer through care. Together, these practices extend the life of buildings, promote material salvage and reuse, and reinforce cultural values that treat materials as valuable resources rather than waste. POLICY PRINCIPLE 4 Reframe building waste as a resource.

12Policy BriefDECARBONIZING THE BUILT ENVIRONMENT THROUGH HERITAGE12 • Directly create or support private investment in materials processing and storage facilities. • Fund research, development, and demonstration projects to help establish salvage and reuse markets. What This Delivers Materials circularity simultaneously advances economic, waste management, and decarbonization goals—keeping more money in the local economy, creating local skilled jobs, reducing pressure on landfill facilities, cutting air pollution, and avoiding carbon emissions associated with producing new materials. The State of Washington Building Code (USA) allows for ungraded salvaged lumber to be reused in construction, creating a pathway for salvaged materials to be repurposed in new construction and renovation projects.25 The CALGreen Building Code (California, USA) is the first mandatory statewide green building code in the U.S. and embeds both material recovery and building reuse into standard compliance pathways.26 The European Union’s Circular Economy Act aims to create a single market for recovered materials, increase regional supply of high-quality recycled materials, and stimulate demand for them across the EU.27 The City of San Antonio’s Circular Economy Program (Texas, USA) is a pioneering deconstruction and salvage policy demonstrating a municipal approach to develop regulatory mechanisms and accompanying initiatives to support workforce training and material redistribution.28 The City of Portland Deconstruction Ordinance (Oregon, USA) was the first municipal deconstruction policy adopted in the U.S. in 2016. The ordinance has diverted significant solid waste from landfills, created jobs in deconstruction, and created pathways for salvaged building materials to be used in new construction.29 Design firm Lendager (Denmark) demonstrates a range of innovative approaches to materials circularity, including a panelized approach to masonry reuse that cuts sections of brick walls from buildings slated for demolition and uses them in prefabricated facades, preserving the original craftsmanship and varying brick patinas.30 Examples, Tools, and Resources

Case Study AGNES COLLEGE13 Barriers to Policymaking Beyond policies themselves, policymaking processes and institutions can hinder heritage- informed decarbonization across climate planning, building regulation, infrastructure investment, and adaptation policy. When heritage and Indigenous perspectives are engaged only after challenges, priorities, and approaches have been established, their technical and cultural solutions cannot be fully implemented. Prevalent approaches to property rights and governance can also restrict communities’ agency to shape policy, implement solutions, and sustain long-term stewardship of their places and practices. Policy Levers • Embed Indigenous and heritage perspectives in climate planning, building regulation, infrastructure investment, and adaptation policy development through early, formal roles for Knowledge-Holders in shaping challenges, priorities, and solutions. • Require that climate plans assess impacts on cultural heritage and living traditions, not just on emissions and risk. • Fund participation for heritage and Indigenous Knowledge-Holders, including compensation for their time and support to develop and implement culture-based climate solutions within communities. • Tie climate funding eligibility to demonstrated inclusion of Indigenous and heritage Knowledge-Holders with evidence of how their contributions shaped priorities and solutions. Including heritage and Indigenous perspectives in decision-making brings vital knowledge about building in balance with the local environment into planning and policy, while leveraging place-based knowledge and enabling communities to shape and implement often-overlooked technical and cultural solutions as part of the all-of-society response needed to address climate change. POLICY PRINCIPLE 5 Include heritage and Indigenous voices in climate policymaking.

14Policy BriefDECARBONIZING THE BUILT ENVIRONMENT THROUGH HERITAGE14 • Enable land trusts, conservation easements, and heritage districts to support community control and long-term stewardship, and recognize these tools as eligible mechanisms for delivering climate outcomes. • Update climate planning guidance to recognize heritage-informed solutions as climate strategies rather than constraints. What This Delivers Deep integration of heritage and Indigenous Knowledge-Holders into decision-making processes leads to policies that draw on the best available solutions from many knowledge systems and can be implemented effectively and respectfully. The Province of British Columbia Indigenous Climate Resilience Capacity Building Program (Canada) invested $2 million to support First Nations in developing advisory groups to provide mentorship, fill knowledge gaps, and implement Indigenous-informed solutions.31 The Kibera Public Space Project (Nairobi, Kenya) is a community network developed to improve the physical, social, and economic conditions of the informal settlement of Kibera by connecting local residents’ perspectives with official policymaking processes.32 The Edisto Open Land Trust (South Carolina, USA) works to protect the island’s Gullah Geechee cultural resources from the impacts of climate change and share the lessons these places can teach in the face of a changing climate.33 Connecting with Country (Australia) is an initiative developed by the Government Architect for New South Wales as a framework for planning, designing, and delivering built environment projects through a place-based approach guided by Indigenous knowledge.34 Historic England (UK) illustrates an effective model for heritage-focused, public-sector bodies to pursue partnerships with and advise other government sectors on leveraging the historic and built environment toward decarbonization, including developing economic market analyses, technical resources, and direct policy guidance.35 Fideicomiso de la Tierra del Caño Martín Peña (San Juan, Puerto Rico) is a community land trust that supports inclusive, community-led decision-making that gives residents long-term control over land and housing management decisions.36 Examples, Tools, and Resources

15Policy BriefDECARBONIZING THE BUILT ENVIRONMENT THROUGH HERITAGE Policymaking Points of Entry » Require whole-life carbon assessments for major building projects, including embodied and operational emissions. » Credit the avoided emissions achieved through continued use, retrofit, and adaptive reuse in targets, funding criteria, and compliance pathways. » Make existing-building upgrades, maintenance, and heritage-informed solutions eligible under climate mitigation programs and incentives. Heritage-informed decarbonization can be integrated into existing climate, heritage, and building policies, including by removing current barriers. The following points of entry connect policy areas with practical actions. Match each action to your agency’s authority and level of government, and identify where coordination with other policies and agencies is needed. » Update heritage guidance and approval processes to enable responsible energy upgrades, restoration of passive features, and careful integration of new materials and systems. » Align heritage and climate incentives to support continued use and circularity, energy efficiency and renewable energy upgrades, and adaptive reuse. » Fund diagnostics, technical assistance, and training for owners and practitioners in heritage-sensitive retrofits and sustainable traditional trades and craft skills. » Develop climate action planning and implementation guidance for heritage sites. » Use land trusts, conservation easements, and heritage districts to strengthen long-term stewardship, delivering critical climate outcomes. Heritage Policy Align heritage protection with decarbonization by enabling responsible adaptation, supporting long-term care, and embedding climate strategies into heritage management. Climate or Emissions Policy Integrate whole life carbon, recognize avoided emissions, and incorporate existing buildings and heritage-informed solutions.

16Policy BriefDECARBONIZING THE BUILT ENVIRONMENT THROUGH HERITAGE » Establish flexible, performance-based compliance pathways that enable existing and historic buildings to comply without maladaptation and without exempting them from safety or emissions goals. » Approve safe pathways for local, traditional, low- carbon, and salvaged materials through testing, certification, and technical guidance. » Allow passive and occupant-centered heating, cooling, and ventilation strategies to demonstrate compliance through measured outcomes. » Adopt reuse-first zoning and development review that evaluates continued use and adaptation before approving demolition. » Offer expedited permitting, density or height flexibility, and tax incentives for converting existing buildings to housing and community uses. » Use vacancy taxes, registration requirements, and acquisition tools to return vacant and underused buildings to productive use. » Include heritage, Indigenous, local, and community Knowledge-Holders in policy creation from problem definition through implementation and evaluation. » Require climate initiatives to assess effects on cultural heritage, living traditions, local priorities, and community capacity alongside emissions and risk, and to include heritage-informed strategies. » Fund community-led heritage-informed solutions, including stewardship, traditional trades, intergenerational knowledge transfer, and place- based demonstration projects. Climate Planning or Programs Bring heritage and Indigenous Knowledge-Holders into problem definition and solution development, and identify opportunities to advance local priorities alongside emissions reductions. Land Use Policy and Planning Prioritize continued use, remove barriers to adaptation, discourage vacancy and unnecessary demolition, and connect reuse with housing needs. Building Codes and Standards Create appropriate pathways for existing buildings, traditional and low-carbon materials, passive strategies, salvaged materials, and outcome-based performance.

17Policy BriefDECARBONIZING THE BUILT ENVIRONMENT THROUGH HERITAGE » Require applicants to assess building retention— including carbon impacts—before demolition. » Adopt deconstruction requirements with measurable targets for salvage and direct reuse and identify opportunities for salvaged materials to support building maintenance and repair. » Invest in local storage, processing, certification, and marketplaces for salvaged building materials while increasing the cost of landfill disposal. » Leverage materials salvage as an opportunity to foster community by celebrating memory and shared cultural values. » Invest in workforce development to build a new skilled workforce. As builders learn to take old buildings apart, they also learn to repair and build with traditional materials. » Use public projects to demonstrate heritage- informed energy upgrades, adaptive reuse, passive design, and responsible integration of contemporary technology into old buildings. » Require long-term maintenance and adaptation plans for publicly owned buildings and funded projects. » Set procurement requirements and targets for repairable, low-carbon, local, and salvaged materials. Public Buildings or Public Investment Apply a “reuse-first” approach through stewardship, demonstration, research, procurement, and long-term building care. Waste or Circular Economy Policy Prioritize building retention first, then repair, deconstruction, salvage, direct reuse, and material recovery.

18Policy BriefDECARBONIZING THE BUILT ENVIRONMENT THROUGH HERITAGE Responding to Local Priorities Heritage approaches can align community co-benefits with decarbonization. These co- benefits often represent key issues for local governments and communities and can act as effective entry points for advancing heritage- informed decarbonization policies. Affordable and Adequate Housing » Adaptive reuse can create new housing by reactivating underutilized buildings. Pairing reuse with measures to protect affordability can help avoid displacement and depopulation. » Building new housing using locally-informed approaches can create climate-responsive, low-energy housing with local labor while stewarding local knowledge. Human Health and Well- Being » Traditional and Indigenous buildings can create low-energy, habitable spaces in extreme heat and cold using local materials, building forms, and space use. » Local, bio-based materials can reduce harmful chemicals often used in new, manufactured materials and assemblies. Resilience and Adaptation » Adapting existing buildings improves the resilience of inhabitants and communities in preparation for extreme weather and natural disasters. » Heritage holds technical and cultural solutions for climate resilience and adaptation. As local climates change, cross- region sharing can bring this knowledge to places facing new climatic conditions. Economic and Workforce Development » Training in building conservation, maintenance, responsible energy upgrades, deconstruction, and traditional trades and crafts creates skilled jobs. » Compared with the global supply chains of much industrialized new construction, conservation, materials salvage and reuse, and construction with local materials can keep more investment in the local economy. Environmental and Resource Conservation » Building conservation and reuse, together with materials circularity, can significantly reduce the need for raw material extraction and reduce waste. » Heritage and Indigenous approaches to natural resource and landscape stewardship offer models of regenerative land management.

19Policy BriefDECARBONIZING THE BUILT ENVIRONMENT THROUGH HERITAGE Endnotes 1. Global Alliance for Buildings and Construction,Global Alliance for Buildings and Construction, “Global Status Report for Buildings and Construction“Global Status Report for Buildings and Construction 2025–2026,” UN Environment Programme, 2026,2025–2026,” UN Environment Programme, 2026, https://www.unep.org/resources/report/global-https://www.unep.org/resources/report/global- statusreport-buildings-and-construction-2025-2026.statusreport-buildings-and-construction-2025-2026. 2. Built Buildings Lab (2026). Decarbonizing the Built2. Built Buildings Lab (2026). Decarbonizing the Built Environment Through Heritage: The Complete Toolkit.Environment Through Heritage: The Complete Toolkit. Built Buildings Lab.Built Buildings Lab. 3 Heritage Council Victoria. Heritage Council Climate3 Heritage Council Victoria. Heritage Council Climate Action Plan. 2024. https://assets.heritagecouncil.vic.Action Plan. 2024. https://assets.heritagecouncil.vic. gov.au/assets/HCV-ClimateActionPlan.pdf.gov.au/assets/HCV-ClimateActionPlan.pdf. 4 Cities Alliance. Back to the Future: Heritage-Centric4 Cities Alliance. Back to the Future: Heritage-Centric Approaches to Climate Resilience in MENA Cities.Approaches to Climate Resilience in MENA Cities. 2024. https://www.citiesalliance.org/sites/default/2024. https://www.citiesalliance.org/sites/default/ files/2024-06/heritage-centric_approaches_to_climate_files/2024-06/heritage-centric_approaches_to_climate_ resilience_in_mena_cities.pdf.resilience_in_mena_cities.pdf. 5 EURAC. “Historic Building Energy Retrofit Atlas.”5 EURAC. “Historic Building Energy Retrofit Atlas.” Database. HiberAtlas, 2019. https://hiberatlas.eurac.Database. HiberAtlas, 2019. https://hiberatlas.eurac. edu/de/willkommen-bei-uns-1.html.edu/de/willkommen-bei-uns-1.html. 6 Sustainable Traditional Buildings Alliance. “STBA6 Sustainable Traditional Buildings Alliance. “STBA Guidance Wheel.” Sustainable Traditional BuildingsGuidance Wheel.” Sustainable Traditional Buildings Alliance, 2020. https://stbauk.org/guidance-wheel/.Alliance, 2020. https://stbauk.org/guidance-wheel/. 7 Consiglio Nazionale delle Ricerche, Istituto di Scienze7 Consiglio Nazionale delle Ricerche, Istituto di Scienze del Patrimonio Culturale, “Built hEritage sustainabledel Patrimonio Culturale, “Built hEritage sustainable CONservation,” accessed June 3, 2026, https://www.CONservation,” accessed June 3, 2026, https://www. ispc.cnr.it/en/2025/02/24/beacon/.ispc.cnr.it/en/2025/02/24/beacon/. 8 Jyoti Soni Dhanak and Antonio Roberto Quiroz Soto,8 Jyoti Soni Dhanak and Antonio Roberto Quiroz Soto, “Keeping Building Traditions Alive: Mason’s Ink’s Work“Keeping Building Traditions Alive: Mason’s Ink’s Work with Women Masons in India,” International Networkwith Women Masons in India,” International Network for Traditional Building, Architecture & Urbanismfor Traditional Building, Architecture & Urbanism (INTBAU), November 6, 2024, https://www.intbau.org/(INTBAU), November 6, 2024, https://www.intbau.org/ keeping-building-traditions-alive-masons-inks-work-keeping-building-traditions-alive-masons-inks-work- with-women-masons-in-india/.with-women-masons-in-india/. 9. See note 1.9. See note 1. 1010 Fairer Westminster, and Westminster City. WestminsterFairer Westminster, and Westminster City. Westminster Retrofit First Policy Guidance. November 2024. https://Retrofit First Policy Guidance. November 2024. https:// www.westminster.gov.uk/media/document/ev-r-004-www.westminster.gov.uk/media/document/ev-r-004- retrofit-first-policy-guidance-for-environment-spd-retrofit-first-policy-guidance-for-environment-spd- november-2024.november-2024. 1111 NYS Parks, Recreation and Historic Preservation.NYS Parks, Recreation and Historic Preservation. “Historic Rehabilitation Tax Credit Programs.” New“Historic Rehabilitation Tax Credit Programs.” New York State. https://parks.ny.gov/preservation/York State. https://parks.ny.gov/preservation/ programs/tax-credit.programs/tax-credit. 1212 Business.Gov.Nl. “Notification of AvailabilityBusiness.Gov.Nl. “Notification of Availability and Letting of Vacant Accommodation.” https://and Letting of Vacant Accommodation.” https:// business.gov.nl/regulations/notifying-letting-vacant-business.gov.nl/regulations/notifying-letting-vacant- accommodation/#art:repurposing-vacant-buildings.accommodation/#art:repurposing-vacant-buildings. Acknowledgments This report draws from Decarbonizing the Built Environment Through Heritage: The Complete Toolkit, developed through an initiative of the Climate Heritage Network led by Built Buildings Lab with Architecture 2030, the National Trust for Historic Preservation, and the Architecture & Urbanism Research Hub – University of Lagos. We gratefully acknowledge these partners and the wider network of collaborators for their contributions. The Decarbonizing the Built Environment Through Heritage initiative, including development and disse

20Policy BriefDECARBONIZING THE BUILT ENVIRONMENT THROUGH HERITAGE 1313 Los Angeles City Planning. “Adaptive Reuse.” LosLos Angeles City Planning. “Adaptive Reuse.” Los Angeles City Planning, City of Los Angeles, 2026.Angeles City Planning, City of Los Angeles, 2026. https://planning.lacity.gov/project-review/adaptive-https://planning.lacity.gov/project-review/adaptive- reuse.reuse. 1414 Architecture 2030. Carbon Avoided Retrofit EstimatorArchitecture 2030. Carbon Avoided Retrofit Estimator (CARE Tool). n.d. https://www.caretool.org/.(CARE Tool). n.d. https://www.caretool.org/. 1515 Build Change, “Saving Embodied Carbon throughBuild Change, “Saving Embodied Carbon through Strengthening Existing Housing,” November 2023,Strengthening Existing Housing,” November 2023, https://embodiedcarbon.climateresilienthousing.org/.https://embodiedcarbon.climateresilienthousing.org/. 1616 ICOMOS Expert Group on EPBD and Implementation.ICOMOS Expert Group on EPBD and Implementation. European Energy Performance of Buildings DirectiveEuropean Energy Performance of Buildings Directive and Cultural Heritage. ICOMOS, 2026.and Cultural Heritage. ICOMOS, 2026. 1717 Office of Public Works. “Improving the EnergyOffice of Public Works. “Improving the Energy Performance of Heritage Properties in State Care.”Performance of Heritage Properties in State Care.” Ireland Office of Public Works, Government of Ireland,Ireland Office of Public Works, Government of Ireland, April 15, 2026. https://www.gov.ie/en/office-of-public-April 15, 2026. https://www.gov.ie/en/office-of-public- works/campaigns/improving-the-energy-performance-works/campaigns/improving-the-energy-performance- of-heritage-properties-in-state-care/.of-heritage-properties-in-state-care/. 1818 Indigenous Climate Action. “Indigenous Climate ActionIndigenous Climate Action. “Indigenous Climate Action Toolkit.” Indigenous Climate Action, Indigenous ClimateToolkit.” Indigenous Climate Action, Indigenous Climate Action. https://www.indigenousclimateaction.com/Action. https://www.indigenousclimateaction.com/ toolkit-page.toolkit-page. 1919 Construction Industries Division of the Regulation andConstruction Industries Division of the Regulation and Licensing Department. “2021 New Mexico EarthenLicensing Department. “2021 New Mexico Earthen Building Materials Code.” https://www.srca.nm.gov/Building Materials Code.” https://www.srca.nm.gov/ parts/title14/14.007.0004.html.parts/title14/14.007.0004.html. 2020 Mariam Issoufou Architects. “Hikma CommunityMariam Issoufou Architects. “Hikma Community Complex: Regional Hub for Culture and Education.”Complex: Regional Hub for Culture and Education.” Accessed June 3, 2026. https://www.mariamissoufou.Accessed June 3, 2026. https://www.mariamissoufou. com/3-hikma.com/3-hikma. 2121 McDonald, Bonnie. “The Relevancy Guidebook:McDonald, Bonnie. “The Relevancy Guidebook: How We Can Transform the Future of Preservation.”How We Can Transform the Future of Preservation.” Landmarks Illinois. November 2023. https://Landmarks Illinois. November 2023. https:// www.landmarks.org/relevancy-guidebook/www.landmarks.org/relevancy-guidebook/ TheRelevancyGuidebook.pdf.TheRelevancyGuidebook.pdf. 2222 Sand, Signe, and Morten Ørsager. “MultidimensionalSand, Signe, and Morten Ørsager. “Multidimensional Decision-Making Methodology to Identify anDecision-Making Methodology to Identify an Optimised Solution for Deep Renovation of HistoricOptimised Solution for Deep Renovation of Historic Buildings.” FuturHist. January 31, 2026. https://Buildings.” FuturHist. January 31, 2026. https:// futurhist.eu/wp-content/uploads/FuturHist_D4.1_futurhist.eu/wp-content/uploads/FuturHist_D4.1_ Multidimensional-decision-making-methodology-to-Multidimensional-decision-making-methodology-to- identify-an-optimised-solution-for-deep-renovation-of-identify-an-optimised-solution-for-deep-renovation-of- historic-buildings-1.pdf.historic-buildings-1.pdf. 2323 Corredera, Antonio. “Collaborative Process: NewCorredera, Antonio. “Collaborative Process: New College of Design and Environment by Erik L’Heureux,College of Design and Environment by Erik L’Heureux, NUS SDE.” Metalocus, February 13, 2023. https://www.NUS SDE.” Metalocus, February 13, 2023. https://www. metalocus.es/en/news/collaborative-process-new-col-metalocus.es/en/news/collaborative-process-new-col- lege-design-and-environment-erik-lheureux-nus-sde.lege-design-and-environment-erik-lheureux-nus-sde. 24 Emina Kristina Petrović and Caroline Ann Thomas,24 Emina Kristina Petrović and Caroline Ann Thomas, “Global Patterns in Construction and Demolition“Global Patterns in Construction and Demolition Waste (C&DW) Research: A Bibliometric Analysis UsingWaste (C&DW) Research: A Bibliometric Analysis Using VOSviewer,” Sustainability 16, no. 4 (2024): 1561,VOSviewer,” Sustainability 16, no. 4 (2024): 1561, https://doi.org/10.3390/su16041561.https://doi.org/10.3390/su16041561. 2525 Washington State Building Code, Chapter 19.27 RCWWashington State Buil