Constructing accessory dwelling units (ADUs) in California will get much easier starting January 1, 2017 thanks to new parking regulations. Also referred to as secondary units or granny units, ADUs are self-contained housing units built to accompany a main dwelling on the same property. ADUs are sometimes built onto or even within the principal dwelling (e.g., a converted garage), but often they are small detached structures consisting of one to two bedrooms plus additional living space. Although property owners build them for personal motivations (e.g., a source of rental income; housing for a relative, caretaker or guests), ADUs are another way to increase urban infill, diversify housing options and increase affordability without significantly changing the character of existing neighborhoods. When added legally, they can also increase property tax revenue.
Despite their benefits, construction of ADUs has long been stymied by local zoning regulations – particularly those related to parking. Two pieces of state legislation passed in 2016 will make building ADUs easier in California. SB 1069 relaxes the parking requirements in certain circumstances. Property owners can now build ADUs without providing any additional parking in the following circumstances:
In cases where these conditions don’t apply, AB 2299 has set a parking maximum of one space per unit or bedroom. It also states that the parking requirement may be satisfied with tandem parking rather than requiring a dedicated space or driveway.
Notwithstanding other zoning requirements that must still be met—including minimum lot size, ADU square footage minimums or maximums, height limits as well as setbacks—the elimination of onerous parking requirements will mean more property owners can receive ministerial approval of their ADU project rather than go through an expensive design-review process.
Reducing the costs unnecessarily burdening ADU projects means that property owners can afford green building measures that may have a higher capital cost but save energy and reduce emissions. For example, even applying for a conditional use permit can easily cost upwards of a thousand dollars. This money can cover the cost difference between standard and ENERGY STAR certified appliances that lowers energy bills. Avoiding the cost of additional parking could pay for solar energy systems.
Looking specifically at the San Francisco Bay Area, reducing the parking requirements will also provide a huge boost to the regional housing supply. UC Berkeley researchers carried out a study of five East Bay neighborhoods within a half-mile of BART train stations. They found roughly 22 percent of parcels in the station areas could accommodate even under zoning requirements with more stringent parking requirements. They estimated that modifying the parking requirements in the station areas, just as what will happen starting in the new year, would make up to 40 percent more parcels eligible for ADUs. In another working paper (“Yes in My Backyard”), they report that the potential market for new ADUs was roughly 31 percent of single-family residential (SFR) properties based on a survey of property owners. The most common reason cited for not yet building an ADU was meeting the parking requirements (MPRs). With the recent legislation overriding local MPRs, a huge barrier has been removed.