Accessory Dwelling Units as Low-Income Housing: California’s Faustian Bargain

Abstract

In 2003, California allowed cities to count accessory dwelling units (ADU) towards low-income housing needs. Unless a city’s zoning code regulates the ADU’s maximum rent, occupancy income, and/or effective period, then the city may be unable to enforce low-income occupancy. After examining a stratified random sample of 57 low-, moderate-, and high-income cities, the high-income cities must proportionately accommodate more low-income needs than low-income cities. By contrast, low-income cities must quantitatively accommodate three times the low-income needs of high-income cities. The sample counted 750 potential ADUs as low-income housing. Even though 759 were constructed, no units were identified as available low-income housing. In addition, none of the cities’ zoning codes enforced low-income occupancy. Inferential tests determined that cities with colleges and high incomes were more probable to count ADUs towards overall and low-income housing needs. Furthermore, a city’s count of potential ADUs and cities with high proportions of renters maintained positive associations with ADU production, whereas a city’s density and prior compliance with state housing laws maintained negative associations. In summary, ADUs did increase local housing inventory and potential ADUs were positively associated with ADU production, but ADUs as low-income housing remained a paper calculation.