In nearly every major city in the U.S., buildings consume more energy and are responsible for more carbon pollution than any other end-use sector—even more than their transportation or industrial sectors. If cities want to be more competitive and more resilient against energy and climate-related crises, they must boost the energy efficiency of their building stock.

The City Energy Project was a pioneering joint national initiative of IMT and the Natural Resources Defense Council that sought to create healthier and more prosperous cities by improving the energy efficiency of buildings. From 2014 to 2021, the Project worked in parntership with 20 participating cities across the U.S. to support and advance innovative and practical solutions that reduce pollution, boost local economies, and create healthier environments.

The City Energy Project empowered participating cities to implement locally designed energy efficiency strategies and fostered peer-to-peer sharing of knowledge and best practices. Each city received technical and strategic assistance to design, plan, and implement a suite of solutions that advanced local sustainability goals, as well as the assistance of staff working on site. Each CEP city developed its own plan and goals regarding sustainability, and the various measures promoted by the Project worked in concert to create benefits greater than any single policy or program could achieve.

The 20 participating cities were:

Map of city energy project cities

The City Energy Project Resource Library, a free, comprehensive online resource captures the best practices pioneered through the City Energy Project so that other cities can significantly boost energy efficiency in buildings. It pairs informed guides, tools, templates, and checklists with curated city-specific, real-world examples pulled from City Energy Project cities to help city sustainability offices, mayor’s offices, and other local leaders customize their energy efficiency efforts for maximum return in their individual jurisdictions.

The City Energy Project was funded by a partnership of Bloomberg Philanthropies, the Doris Duke Charitable Foundation, and The Kresge Foundation. To learn more about the project and its legacy library, visit