The purpose of this report is to assess whether racial or income-based disparities exist in where accessory dwelling units (ADUs) have been built following reforms pioneered by the Bay Area Council through its sponsored legislation, SB 1069 (Wieckowski). As an evidence-based advocacy organization that has invested significant effort in expanding California’s ADU laws, the Bay Area Council undertook this analysis to evaluate the effectiveness of those reforms and to inform its ongoing policy work.
ADU Construction and Racial Equity in California
Executive Summary
Accessory dwelling units, or ADUs, have made tremendous progress in addressing California’s immense housing shortage, but there has been too little research into their specific impacts on equity in California. This paper attempts to help close that shortfall by investigating whether ADUs have been a tool for increasing wealth and housing options for people of color and low and moderate-income households in California.
We analyze the populations that are building ADUs by looking at where ADUs are currently being permitted and overlaying that with known characteristics of wealth and race. Some have argued ADUs mostly benefit and exist in wealthier neighborhoods, as these households have the financial means to build the units, but we find little to no income disparity in where ADUs are permitted.
Key findings include:
ADU production happens more in white neighborhoods
ADU production in predominantly white census tracts is higher than would be expected based on their share of the population.
ADU production occurs less in high-income areas
Low- to moderate-income census tracts accounted for a larger share of ADUs, again a disproportionate concentration.
41 percent of ADUs were permitted in “redlined” areas
41 percent of ADUs permitted in 2023 were in areas that were marked as “declining” or “hazardous” by the Home Owners’ Loan Corporation in historical redlining maps, also an overrepresentation.
These findings suggest ADUs are not just a means for wealth accumulation in high-income areas, adding to existing research finding that ADUs can be a promising solution for building affordable housing and increasing density in neighborhoods with exclusionary zoning.