Accessory dwelling units, better known as “in-law apartments” or “granny flats,” have long been recognized as a valuable and essential component of California’s response to the state’s worsening housing shortage. So essential in fact, state law establishes a right to build ADUs, severely limiting local governments’ restrictions on new ADU development. Despite this state law, the city of San Marino adopted building code restrictions that forbid homeowner Cordelia Donnelly from adding an ADU over her garage. Because state law dealing with ADUs fully preempts local restrictions, Cordelia asked the California Supreme Court to recognize her right to create more housing.
Cordelia Donnelly thought an accessory dwelling unit—or granny flat—would be a wonderful value-add to her San Marino, California home. So, in 2017, she applied for a permit to build an ADU above her garage, which is unattached to her house.
After many rounds of correspondence, demands, and clarifications, the city denied Cordelia’s application for failing to comply with three zoning requirements: a minimum lot size, a maximum ADU size, and a ten-foot separation between each structure.
In other words, the city denied Cordelia’s permit because her lot was too small, her proposed ADU was too big (but exactly the same footprint as the garage), and her garage was too close to the house.
In doing so, however, San Marino overstepped its authority. State law not only prohibits local governments from enforcing such exclusionary land-use restrictions for ADUs, it also preempts efforts like San Marino’s to hinder and delay new ADU development.
The state’s ADU law dates back to 1981, when, in an effort to alleviate California’s worsening housing shortage, new legislation declared ADUs to be valuable and essential components of the state’s housing supply. Since that time, however, local governments throughout California have avoided this mandate and continue to resist new ADU construction with their own onerous, exclusive zoning rules, such as minimum lot sizes and single-family zoning.
The state tried to clamp down on such heavy-handed local restrictions by amending the law in 2002, 2016, and 2019. In fact, current state law specifically nullifies any local ADU provisions that are inconsistent with state law.
So, when the city denied Cordelia’s permit application, she sued, arguing that state law preempts the city’s requirements. The trial court agreed with her in part but upheld the denial. An appellate court affirmed the decision, and, in doing so, it also removed an important, state-sanctioned protection for property owners like Cordelia.
Represented by PLF, Cordelia asked the California Supreme Court to review the case and recognize her freedom to productively use property to create much-needed new housing. The court had the opportunity to show California cities that they must follow state law and stop placing unfair burdens and limitations on new ADU development.