Accessory dwelling units (ADUs) or “granny flats” have exploded in popularity since lawmakers reduced barriers to construction in 2016. They’re an imperfect tool to ease the housing crunch. While they add to inventory, research has raised significant equity and segregation concerns associated with ADUs.
And yet, in some affluent San Mateo County cities, up to 80% of state-mandated affordable housing now consists of ADUs. That’s according to a new report from the San Mateo County Civil Grand Jury, entitled "Accessory Dwelling Units: Affordable Housing's Panacea or Prevarication?"
As the Grand Jury notes, there are few regulations to ensure that ADUs get rented to low-income individuals. These structures are frequently rented to friends or relatives of the homeowners and they're not typically feasible for families.
By counting these structures as affordable housing, wealthy cities are able to bypass construction of deed-restricted multifamily residences which do much more to alleviate the housing crisis. As a result, affordable housing exits “solely on paper and never in operation,” the Grand Jury writes.
Reliance on ADUs to meet housing goals is a countywide phenomenon. But it's most prominent in Atherton, Hillsborough, Portola Valley and Woodside, according to the report.
The Grand Jury recommends that San Mateo County and its cities “immediately stop using ADUs to meet their State-mandated very low-, low-, and moderate-income housing targets in their Housing Element submissions until they have also proposed an effective monitoring system that verifies how newly developed ADU’s will be used.” A verification system that can determine how ADUs are being used should be developed by February 1, 2024.
San Mateo County and its cities have six months to respond to the report.
Read the document here.