San Francisco runs parallel Local and State ADU programs with very different rules. The Local Program allows unlimited converted ADUs in buildings with 5+ legal dwelling units (plus one detached) — far beyond state baseline.
Varies by program. JADU up to 500 sq ft. Local Program counts allowed ADUs by existing/proposed legal dwelling units (e.g. up to 4 units: 1 ADU + 1 detached; 5+ units: unlimited converted ADUs + 1 detached).
State guarantee: California requires every city to allow at least an 800 sq ft ADU exempt from local lot coverage, FAR, and front-setback rules.
Height baseline: 16 ft for detached, rising to 18 ft within ½ mile of major transit. Attached ADUs follow the primary home, capped at 25 ft.
State Program ADUs follow state ministerial parking rules. Local Program ADUs follow Planning Code path with applicable waivers (Planning Director Bulletin No. 3).
Apply via city online steps (sf.gov ADU topic). Local Program uses Planning in-house review. State Program includes Permit Review Roundtable with a 60-day target. DBI handles building permit/construction.
State backstop: A complete ADU permit must receive a decision in 60 business days. If the city stalls past 30 business days, AB 253 lets you hire a certified private plan checker to force a 10-business-day decision.
Local Program may trigger Costa-Hawkins Regulatory Agreement tying new ADUs to rent control when Planning waivers granted. Use Planning impact-fee/development calculators.
SB 543: No impact fees on ADUs ≤750 sq ft. Above 750 sq ft, fees scale to the ratio of ADU size vs the main home.
Visit the official San Francisco ADU page (link in hero) for current eligibility and downloads.
Standard ADUs in San Francisco: no owner-occupancy required (made permanent in 2023).
JADUs: limited to 500 sq ft of interior livable space within an existing single-family home. Owner occupancy is required only when sanitation facilities are shared with the main house. JADUs cannot be used as short-term rentals (AB 1154 / SB 543).
Sketch a floorplan, walk through it in 3D, and have our planners review it for size, height, and setback compliance before you submit to San Francisco.
Heads up: Local rules change frequently. This page summarizes publicly available state law (California Government Code §§ 66310–66342) and current local guidance for general planning purposes. Always confirm specifics with the San Francisco planning desk before submitting plans. ADUMetrics does not provide legal advice.