ADU rules in San Francisco

Both programs allow detached ADUs. State program (Sec. 207.2, implementing Gov. Code 66323): one detached new-construction ADU on a lot with an existing or proposed single-family home, combinable with one converted ADU and one JADU; on multifamily lots, two detached ADUs where the multifamily building is proposed, or up to eight (never more than the number of existing units) where it already exists, per Planning Director Bulletin No. 3 (June 2026). Local program (Sec. 207.1): ADUs inside the buildable area or inside an existing authorized detached garage or other auxiliary structure, plus one additional detached ADU in the required rear yard with 4 ft side and rear setbacks and a 16 ft height limit.

State program: one attached ADU under Sec. 207.2(d), the Gov. Code 66314 track, which may not be combined with any other ADU or JADU on the lot; converted ADUs inside the existing or proposed home (including attached garages and storage areas) and JADUs use the streamlined Gov. Code 66323 track instead. Local program: ADUs inside the buildable area or the existing built envelope, with no vertical additions except a raise of up to 3 ft for a building undergoing seismic retrofitting and a one-story expansion of a legal nonconforming garage or auxiliary structure on a corner lot.

The Planning Code states these caps in Gross Floor Area, while Gov. Code 66321(b), as amended by SB 543 effective 1-1-2026, bars a maximum below 850/1,000 sq ft of interior livable space, and Bulletin No. 3 already states the attached caps and the fee threshold in interior livable space; where the two measures differ, the state floor should govern. No city rule may block an 800 sq ft, 16 ft ADU with 4 ft side and rear setbacks (Sec. 207.2(d)). State-program height limits are 18 ft detached plus 2 ft to match the main roof pitch (Bulletin No. 3 says 16 to 18 ft on multifamily lots) and 25 ft attached; the local rear-yard detached ADU is capped at 16 ft. A local-program ADU that takes space from an existing unit may use no more than 25% of the ground and basement habitable floor area unless the Zoning Administrator waives the limit.

Neither Sec. 207.1 nor Sec. 207.2 imposes an owner-occupancy requirement on an ADU under either program. The one exception is a junior ADU that shares sanitation facilities (a bathroom) with the main home: Bulletin No. 3 says the owner must then record a deed restriction that includes owner occupancy of either the JADU or the main house, following Gov. Code 66333. Sec. 207.2(h) separately requires a recorded Notice of Special Restriction on any lot with a JADU (no separate sale; size and attributes per Gov. Code 66333).

SF.gov's ADU design-standards page states that 'Additional parking is not required for an ADU,' and the Planning Code's parking article (Article 1.5) carries no schedule of required residential spaces, only Sec. 151.1's schedule of permitted accessory spaces. The garage-replacement waiver is explicit in Sec. 207.2(d)(8) for the state program.

No conditional use authorization in either program; ADUs go through a building permit. State-program ADUs are ministerial: a 60-day review from a complete application, no CEQA review, no discretionary review requests, no Planning Commission hearing, no appeal, and no Sec. 311 neighborhood notification (Sec. 207.2(e); Bulletin No. 3). Local-program ADUs require a Rent Board declaration on tenant housing services, cleared before approval, and a notice posted in the building at least 15 days before applying; they are exempt from Sec. 311 notification when built entirely within the existing built envelope, and the Zoning Administrator may waive density, bicycle parking, rear yard, exposure and open space standards under Sec. 307(l).

The local-program STR ban is recorded as a Notice of Special Restriction (Sec. 207.1(d)); the state-program ban is Sec. 207.2(f). Separate sale or financing is barred (Sec. 207.1(e), 207.2(g), 207.2(h)(1)) except for ADUs meeting Gov. Code 66341, state-program ADUs meeting Sec. 207.4 and Subdivision Code Sec. 1316 (Bulletin No. 3: one non-JADU ADU on a lot with four or fewer units, applied for on or after 5-1-2025), and local-program ADUs in buildings that were all condominiums on 7-11-2013 with no listed evictions since 7-11-1996. The local Regulatory Agreement invokes the Costa-Hawkins exception in Civil Code 1954.52(b) but keeps the owner's right to set the initial rent (Sec. 207.1(h)).