Off-grid site report
San Francisco County, CA
37.7867, -122.4948 · 226 ft elevationRead this before you act on anything below. This is my researched starting point for San Francisco County, CA, not legal advice and not a guarantee. Rules change, and the deciding facts on any specific parcel (setbacks, perc results, overlay districts, deed restrictions, road frontage) live at the county or town office, not in any database. Before you buy land or build, confirm the current rules directly with the local zoning and health offices - the sources on this page tell you exactly who to call.
The local rulesSan Francisco County, CA
Zoning & raw-land occupancy
RestrictedI found that San Francisco is a fully urban city-county with no unincorporated 'raw land' or rural zoning; every parcel falls under the Planning Code, and living outside an approved dwelling isn't a recognized land use here, it's handled through code enforcement instead. Check with SF Planning for your specific parcel's zoning. source
Dwellings, tiny homes & RVs
RestrictedSan Francisco has actively cracked down on long-term RV living, including a citywide two-hour parking limit for RVs and oversized vehicles, with only a narrow, time-bound transition program for those already registered. There's no legal path I found to live long-term in an RV or tiny home on wheels as a standalone residence here, though I couldn't confirm this through an official municipal code page, only news reporting.
Building permits & codes
RestrictedAny dwelling construction, including ADUs, has to go through San Francisco's Department of Building Inspection and Planning under the local Building Code and Planning Code, on top of the state's Title 24 rules. For example, ADU studio units have specific minimum floor area and ventilation standards you'd need to confirm with DBI before building. source
Septic & composting toilets
RestrictedSan Francisco is almost entirely on municipal sewer, so individual septic systems aren't a normal feature here and there's no dedicated county septic-permitting page like you'd find in rural counties. Any on-site wastewater or water reuse system instead needs sign-off through the city's onsite water reuse program, run jointly by SFPUC and the Department of Public Health. source
Greywater reuse
Generally allowedFor one- or two-unit homes, a simple laundry-to-landscape greywater system that doesn't alter existing plumbing doesn't need a permit, as long as it follows the city's guidelines. Any more involved greywater system requires a permit from the Department of Building Inspection, so it's worth checking with them first. source
Rainwater harvesting
Generally allowedBasic rooftop rainwater collection follows the state baseline and is allowed, but if you want to reuse rainwater indoors (like for toilets or laundry) or run a larger system, you'll need to go through SFPUC and the Department of Public Health's onsite water reuse review. San Francisco has even built its own rainwater harvesting calculator to help with this. source
Private wells & water rights
RestrictedUnlike rural counties, San Francisco requires city-level authorization for any groundwater withdrawal, not just a construction permit. The Public Utilities Commission reviews and grants authorization to withdraw groundwater, while the Department of Public Health enforces well construction and operation rules and issues the actual Permit to Operate. source
Living disconnected from utilities
Unclear - verifyI couldn't find a specific San Francisco ordinance addressing voluntary full utility disconnection for an occupied home; it would likely fall under general Building and Housing Code habitability standards enforced by DBI. Given the city's active enforcement against unconventional dwellings like RVs, I'd expect scrutiny here, but this specific point is not confirmed, so it's worth calling DBI directly to ask.
Sun30-year normals
- Peak-sun hours, annual average
- 5.3 hrs/day
- Worst month (sizes an off-grid array)
- 3.7 hrs/day
- Yearly output per 1 kW of panels
- 1,506 kWh
JFMAMJJASOND
Weather1991-2020
- Precipitation
- 24 in/yr
- Heating degree days
- 2,909 (mild)
How far help isstraight-line
- Hospital
Menlo Park Surgical Hospital - 29.0 mi
- Fire station
Muir Beach Volunteer Fire Deparment - 7.0 mi
- Hardware store
Ace - 0.7 mi
- Grocery
Calmart - 2.3 mi
From OpenStreetMap. Road miles will be longer, often much longer in hill country.
Plan this spot
These open with this location's real numbers already filled in (ZIP 94121).
Size a solar systemHeat loss & insulationFirewood per winterRainwater harvestGarden sizePanel tilt
Looking at a specific parcel in San Francisco County, CA?The rules above are the jurisdiction. The land check runs the parcel itself: flood zone, soils and septic suitability, wetlands, slope, access, climate, and these verdicts, from a parcel number or coordinates.
Check a parcel →Share or save this report:New report
Sources: US Census Bureau geocoder; NLR PVWatts v8 (solar); NOAA NCEI 1991-2020 climate normals (nearest station) or Open-Meteo (ZIP-centroid) for weather; Open-Elevation; OpenStreetMap contributors. Public data retrieved Aug 22, 2026; agencies update their layers on their own schedules. Planning data, not a survey or legal advice.
New here, or not sure where this fits? Start here walks through the whole thing in order.