The Rise of the In-Law Unit
Across the country, many cities facing housing shortages are restructuring their rules and regulations regarding in-law units. Colloquially known as “granny flats”, these pint-sized units are technically called Accessory Dwelling Units (or “ADUs”). In San Francisco, the Board of Supervisors recently approved a new bill that will relax the rules governing ADUs, with the hope that this will create “30,000 more affordable housing units in privately owned buildings to help with the housing crisis”.
FifthArch recently evaluated the new ADU Program for the Alabama Street renovation project. This single-family residence has a ground-floor garage level with additional unfinished habitable space. This is a common scenario for many homes in the city, and is listed by SF Planning as a prototype suitable for ADUs.
For the Alabama Street project, we considered renovating that unfinished garage space into a separate living unit with its own bath and kitchenette. This would provide another potential rental income, to help with the outrageous cost-of-living expenses in San Francisco. But without the new ADU Program, adding a separate “rental unit” would be extremely difficult.
First, this single-family house is zoned RH-1. This means that the property may have only one dwelling unit. If your property is zoned RH-2 or has no density controls, then this is not an issue. But for this subject property, this is a hurdle in adding a second unit. The new ADU Program, however, overrides this limitation by allowing any existing residential building to add one ADU, regardless of other density controls (and for buildings with 5 or more units, you can add as many ADUs as you want).
There are also other hurdles in adding a unit. For example, a new unit may trigger additional parking requirements. With the ADU Program, you can replace parking spaces with sheltered, indoor bicycle parking. Other controls such as rear yard, open space and exposure requirements may also be waived under the new regulation.
What cannot be waived, however, are building code requirements that ensure life safety. For instance, the unit must still maintain a minimum 7'-6" ceiling height for living spaces (and 7'-0" ceiling height for kitchens, bathrooms, halls, laundry rooms). Units also cannot exit through a garage, without a fire-rated hallway. And more importantly, the unit must still meet exiting requirements.
Specifically, the California Building Code requires a minimum of 2 exits for most buildings. For residential buildings, a single exit may be allowed if your ADU has rescue openings, upgraded fire resistance in the ceiling assembly and a fire sprinkler system covering the entire ground floor. This may sound stringent; however, a pre-application meeting with the Department of Building Inspection and the Fire Department can determine if there are applicable “equivalencies” for meeting the Building Code.
For instance, the state building code requires rescue openings (such as in windows) to “open directly into a public way or to a yard that opens to a public way”. If your unit’s bedroom is facing the rear of house, then your windows may not open to the street. In this scenario, San Francisco has an exception (a “local equivalency”) that allows your rescue opening to open to the rear-yard, as long as it is 25' deep.
In summary, the ADU Program may be a great option for adding an income-producing living unit, where one would have been difficult to add before. Despite relaxed planning procedures, however, ADUs must still meet building code requirements. In some situations, meeting the building code will be straightforward; in other scenarios, some creative space planning and design may be necessary.
