Can I Build Tiny Home in San Francisco, CA? (2026)
Find out if you can build a tiny home in San Francisco, CA. Rules, permit requirements, costs, and next steps.
Tiny homes on permanent foundations are allowed in San Francisco, CA. Tiny homes on wheels are not permitted as permanent dwellings.
A tiny home is a small dwelling unit — typically under 400 sq ft — that can be built on a permanent foundation or on wheels. In San Francisco, CA, the rules differ significantly depending on whether the structure is on a permanent foundation (treated as a dwelling unit under building code) or on wheels (treated as a recreational vehicle under vehicle code). Tiny homes on permanent foundations must meet a minimum size of 220 sq ft in San Francisco.
Tiny Home Rules in San Francisco
Tiny Home Rules in San Francisco: Foundation-based tiny homes: Permitted. Tiny homes on wheels (THOWs): Not permitted as permanent dwelling — classified as recreational vehicle. Minimum size: 220 sq ft. SF Residential Building Code requires minimum habitable space per room (70 sqft per habitable room). Micro-units are allowed in SF per Planning Code Section 102 — minimum 220 sqft for new micro-unit construction. Tiny homes on wheels (THOWs) not permitted as permanent dwelling — classified as vehicles, not structures. SF has a notable tiny home and micro-apartment market due to housing costs.
Costs & Fees
Building permit fees for tiny homes in San Francisco follow the same schedule as other new construction. Contact the San Francisco Department of Building Inspection (DBI) through their official website for current fee information.
Next Steps
Next steps for building a tiny home in San Francisco: 1. Determine foundation vs. wheeled — the rules are fundamentally different. 2. For foundation tiny homes, obtain a building permit from the San Francisco Department of Building Inspection (DBI). 3. For wheeled tiny homes, verify whether your property allows RV siting. 4. Check if your tiny home could qualify as an ADU on your property.
San Francisco Department of Building Inspection (DBI)
Frequently Asked Questions
Can I build an ADU (in-law unit) in San Francisco?
What are San Francisco's Airbnb rules?
Short-term rentals in SF require a Certificate of Registration from the Office of Short-Term Rentals ($450/year). Your unit must be your primary residence — you must live there at least 275 days per year. Whole-home (unhosted) rentals are capped at 90 nights per year. Hosted rentals (you're present) have no night cap. Penalties for non-compliance are $484 per day. Register at ostr.sfgov.org.
What zoning system does San Francisco use?
San Francisco uses its Planning Code (not Municipal Code) for zoning. Residential zones are RH (House) and RM (Mixed Residential) — ranging from RH-1 (single-family) to RM-4 (high-density apartments). Neighborhood Commercial Transit (NCT) zones allow retail below residential. The Planning Code emphasizes rear yard preservation — the typical requirement is 25% of lot depth or 15 ft minimum for rear yards in most residential zones.
Do I need a permit to run a business from my home in San Francisco?
Yes. A Home Occupation Permit ($148 fee) is required for any business operated from a residence in San Francisco. Restrictions apply: no clients visiting, no non-resident employees, no external signs, and business use must be secondary to residential use. Violations can result in code enforcement action.
What are the front yard setback requirements in San Francisco?
In RH-1 (single-family) zones, the standard front setback is 15 feet from the front property line. However, SF Planning Code requires that new construction match the prevailing setback of the block face — if neighboring homes have deeper setbacks, yours must match. Side yards are typically 0 feet in SF's characteristic attached rowhouse pattern. Rear yards must be at least 25% of lot depth (minimum 15 ft).
Are solar panels required on new homes in San Francisco?
Yes. California's Title 24 Energy Code (effective 2020 for single-family) requires solar PV on all new low-rise residential construction. San Francisco also adopted its own solar mandate for commercial buildings in 2016. Properties in SF historic districts need Planning Department approval for solar panels visible from the street, but this cannot be denied for code-compliant systems.
How do I find the zoning for my San Francisco property?
Use the SF Planning Department's online map at sfplanning.org/zoning-map. Enter your address to find your parcel's zone designation, height/bulk district, and any overlay districts. You can also look up whether your property is in a historic district or on the list of individually designated landmarks.
Source: San Francisco Department of Building Inspection (DBI) — Building Regulations. Last verified April 5, 2026. View source