Lakewood, CA Accessory Structures: ADU Rules (2026)

21a governs Accessory Dwelling Units across every zone that allows single-family or multifamily housing, reflecting how much of Lakewood's postwar tract stock is single-family R-1 lots. On an R-1, R-A, A, or PD-SF lot, the City approves up to two ADUs ministerially through a Building and Safety plan check, with no discretionary hearing, so long as the primary dwelling either exists or is built concurrently. Multifamily lots get their own allowance: up to eight detached ADUs on an existing complex, capped at the number of existing attached units, plus internal conversions of up to twenty-five percent of existing units.

Development standards apply regardless of zone. An ADU needs a minimum four-foot side yard and four-foot rear yard setback, and a twenty-foot front yard setback unless it qualifies for the state law exception letting an ADU up to 800 square feet project into the front setback. Floor area runs from a 150 square-foot minimum up to 1,200 square feet, though a conversion of existing floor area can exceed that cap, and an ADU attached to the primary house tops out at fifty percent of that house's floor area unless it stays under 800 square feet.

Height is capped at two and a half stories or thirty-five feet for new construction, twenty-five feet if attached and in the front yard, or eighteen feet if detached and in the front yard. Every detached new ADU has to install solar panels to offset its electrical demand, and the City has to complete plan check review within sixty business days or the permit is deemed approved.