This report identifies transportation-efficient, healthy, high-opportunity areas for housing development. Adding both market-rate and below-market-rate housing in these areas could promote housing affordability and reduce greenhouse gas emissions, while contributing to enhanced socioeconomic mobility and more equitable development patterns. The development potential in the identified areas, according to data provided by regional planning organizations and local jurisdictions, substantially exceeds the number of existing units, but the layering of regulatory restrictions may impede development at the putatively planned densities. This report therefore identifies enhanced data collection procedures and policy levers to promote development in the identified areas. The policy levers include regulatory changes to expedite the approval of infill housing, to increase the financial feasibility of infill housing, and to more effectively target regulatory requirements related to the provision of below-market-rate housing units.

Nicholas J. Marantz et al., Evaluating the Potential for Housing Development in Transportation-Efficient and Healthy, High-Opportunity Areas in California, Contract number: 20STC009 California Air Resources Board 1–178 (2024).