4 November 2026
Today we launch a new global effort to bring together evidence across the built environment on the value of green buildings and the cost of inaction.
Building on more than a decade of work tracking the cost and performance of sustainable buildings, we are leveraging our global-regional-local network to collect evidence from around the world.
Contribute your evidence through the Evidence Collection Form.
We invite respondents from all parts of the building and construction sector, from architects, developers, contractors and suppliers, building owners and tenants, to lenders, asset owners and insurers, local or national governments, utility companies, and anyone else in the value chain.
The evidence collection focuses on three areas: the cost of action, including the investment and implementation costs of decarbonisation and climate adaptation; the cost of inaction, including the risks and losses associated with failing to act; and the value preserved or created, from stronger asset performance and operating cost savings to reduced risk and improved access to capital.
Taken together, the submissions will provide a current global dataset to support decision-making across industry, finance and government. We encourage everyone to contribute your evidence in this global effort to renew the business case. The findings will be made publicly available in mid-2027.
As policymakers and experts gather in Türkiye for COP31, the initiative seeks to connect this evidence with the growing focus on implementation. The COP31 Presidency is placing a strong emphasis on electrification, energy efficiency and circularity. Buildings are central to delivering all these priorities. Achieving these objectives will require capital at scale, supported by credible evidence of the costs, risks and returns.
Natural catastrophes have cost the global economy an estimated US$20 trillion since 2000. Direct economic losses in 2025 alone reportedly reached US$296 billion, including US$167 billion in uninsured losses. These losses are starting to be reflected in uninsurability of assets in areas prone to natural disasters and higher insurance premiums in certain locations.
Evidence also shows how action at building level can reduce this exposure. For example, in the United States, adopting modern model building codes has been estimated to save US$11 for every US$1 invested, while only adding around 1% to construction costs. Meanwhile, during Hurricane Sally, coastal homes meeting the FORTIFIED Roof standard experienced 72% lower total losses.
Reducing energy demand and electrifying buildings can lower operating costs and limit exposure to fossil fuel dependence and volatile energy prices.
A study of 46,600 offices across 14 global cities found that light to medium retrofits could deliver energy savings of 10–40%, alongside lower running costs and improved resilience to changing regulation.
Evidence from South Africa also shows how these gains can be reflected in investment performance. In 2024, Green Star-certified Prime and A-grade offices delivered a total return of 10.1%, compared with 8.9% for non-certified offices.
Individual studies such as these point to significant value across geographies, asset classes and market conditions. We are using our global, regional and local network to bring this evidence together, and we invite anyone in the built environment value chain to take part.
Submit your data for the Business Case for a Sustainable Built Environment through the Evidence Collection Form.
For more information on the types of evidence we are looking for and how it will be used please read our Guide to the Evidence Collection Form
Deadline for submissions: 31 December 2026