Vallejo, CA Accessory Structures: Garage Conversions (2026)

02(E) states directly that a garage converted to an ADU is considered an attached ADU or JADU, which sets the size cap at fifty percent of the primary unit's floor area or 1,200 square feet, whichever is smaller. 02(G) then removes the normal four-foot side and rear setback requirement specifically for an existing garage converted to an ADU or JADU, or for a conversion of an existing accessory structure into an ADU, and also waives setbacks when placing an ADU inside an existing residence if the fire division confirms adequate side and rear yard access.

02(L) requires one additional off-street space for most new ADUs, but states plainly that no replacement parking is required when a garage, carport, or covered parking structure is demolished or converted to make room for the ADU. That parking requirement can also be waived outright if the converted unit sits within a half-mile of a public transit stop, on a permit-parking street without an available permit, on a street narrower than twenty feet, in a historic district, or within a block of a car-share location. 04, decided by the director within sixty days, without a public hearing or discretionary approval.