How ADUs Can Help Ease the Affordable Housing Crisis

In a report for Brookings, Jenny Schuetz and Eve Devens describe the potential of accessory dwelling units (ADUs), sometimes known as granny flats or casitas, to make a dent in the housing crisis and offer another option for affordable rental housing in residential neighborhoods.

Using Los Angeles as an example, the authors note that one of the keys to expanding ADU stock is homeowner participation. “While ADU production overall has steadily increased in recent years, it is not obvious that the typical Los Angeles homeowner wants to enter a long-term commitment to lease their ADU to low-income renters and comply with the rules governing housing subsidies.”

The authors note that the Los Angeles region offers a useful model for how ADU policies can impact affordable housing production. “In the city of Los Angeles, Los Angeles County, and Pasadena, ADUs account for over two-thirds of all housing permits between 2020 and 2022. However, no data is available on how many of these ADUs are available for rent on the open market, and how many are reserved for personal use or family members.”

The report outlines how four pilot ADU programs in the L.A. area are helping reach housing goals, each with a slightly different emphasis. “The city of Los Angeles focused particularly on matching low-income older adults with ADUs, noting that many seniors are familiar with small homes in low-density residential neighborhoods.” Meanwhile, Los Angeles County reserved ADUs for people experiencing homelessness.

Ultimately, the authors conclude, “To make ADUs a larger segment of the affordable housing market over the coming years will require both more financial support as well as substantially higher take-up rates among homeowners.”