By one estimate, California must build 3.5 million housing units by 2025 to end the state’s housing shortage. This shortage has resulted in rising rents and prices, closed access to homeownership for many families, and forced many Californians to leave the state altogether. A significant body of research suggests that the shortage is the result of land-use regulations that make it difficult to build new housing. But where in California would such housing be built absent regulatory barriers?

To better understand the scale and geography of California’s housing shortage, the California YIMBY Education Fund commissioned a study by MapCraft of relative housing underproduction rates across the state. To do this, we estimate a “conversion rate” for each city and county that compares historical rates of housing permitting to potential market-feasible housing development opportunities, assuming no limitations due to zoning. For example, a jurisdiction might have permitted 1,000 housing units last year while having an estimated 100,000 zoning-free market-feasible housing development opportunities on sites that were not environmentally encumbered, which would amount to a 1% conversion rate.

Key findings of this study include:

The following report briefly outlines the purpose of this study, documents the methodology, discusses topline findings, and considers potential policy implications. A companion spreadsheet includes conversion rates and rankings for each city and county in California, and a companion map depicts these results graphically, along with a statewide map of vacant parcels.

  • Based on a recent point-in-time snapshot of market-feasible housing development opportunities, roughly 30% of the approximately eight million addressable parcels in California could, in the absence of regulatory barriers to new housing, accommodate additional market-feasible units.
    • Many factors preclude this level of development from proceeding concurrently—including labor availability, material supply chains, willing sellers, and zoning regulations—such that California jurisdictions permitted less than 140,000 units per year between 2018 and 2021, an annual conversion rate of less than 1% of statewide market-feasible opportunities.
    • The analysis considered the housing development potential of less than one-tenth of the land area in California. State- and federally-owned properties were not considered. Neither were areas subject to high fire risk, habitats for protected species, wetlands, and other environmental areas of statewide concern. The analysis also excluded sites known to be used for infrastructure or industrial uses.
  • Within California, conversion rates of housing development opportunities vary widely. Among cities, the lowest conversion rates were mainly found in suburbs across the Bay Area and Southern California—especially near the coast—which have enormous housing demand but issue few housing development permits.
    • Examples include jurisdictions like NorcoRancho Santa Margarita, Laguna Hills, and Cerritos.
  • Among counties, the lowest conversion rates of housing development opportunities were found along the perimeter of the Bay Area and along the Central Coast. Both regions face enormous housing demand but have issued few housing development permits in recent years.
    • Examples include counties like MarinNapa, Monterey, and Santa Barbara.
  • Not all of California is underperforming in equal measure. Portions of the Central Valley and Inland Empire are converting market-feasible development opportunities into housing development permits at relatively high rates.
    • Cities like MercedVisaliaStockton, and Bakersfield and counties like KernMerced, and Placer are permitting housing at high rates relative to the state as a whole.

Download and read the full report here

Or read the full report online below

Companion map

Download the spreadsheet here

Vacant parcels map

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