Off-grid site report
Solano County, CA
38.2483, -122.0412 · 13 ft elevationRead this before you act on anything below. This is my researched starting point for Solano 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 rulesSolano County, CA
Zoning & raw-land occupancy
RestrictedSolano County's Chapter 28 Zoning Ordinance and General Plan set allowable uses per parcel in unincorporated areas; there's no countywide allowance for indefinite raw-land occupancy outside a permitted use. source
Dwellings, tiny homes & RVs
Unclear - verifyBuilding & Safety Services enforces the California Building Code, and ADUs require an underlying primary dwelling in specific zones per county code, but rules for tiny homes or long-term RV living on raw land are not confirmed; ask Building & Safety Services directly. source
Building permits & codes
RestrictedSolano County Building & Safety Services requires permits and inspections under the California Building Code for construction in unincorporated areas. source
Septic & composting toilets
Generally allowedChapter 6.4 of the county code sets standards for on-site sewage disposal, administered by the Environmental Health Division's Onsite Sewage Disposal Program, which issues construction permits. source
Greywater reuse
Generally allowedThe Environmental Health Division's Onsite Sewage Disposal Program covers greywater systems alongside septic; complex systems need an annual operating permit under Chapter 6.4, while simple systems likely follow the state exemption. source
Rainwater harvesting
Generally allowedNo county ordinance restricting rooftop rainwater capture was found; the county appears to follow the state baseline, though this is not fully confirmed for larger systems.
Private wells & water rights
RestrictedThe Environmental Health Division's Well Program requires permits for wells and soil borings under county code Chapters 12.10 and 13.10, with construction standards and time-limited permits. source
Living disconnected from utilities
Unclear - verifyNo standalone county ordinance on off-grid utility disconnection was found; it's addressed indirectly through building permit and health code compliance handled by Building & Safety and Environmental Health.
Sun30-year normals
- Peak-sun hours, annual average
- 5.9 hrs/day
- Worst month (sizes an off-grid array)
- 3.5 hrs/day
- Yearly output per 1 kW of panels
- 1,666 kWh
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Weather1991-2020
- Precipitation
- 25 in/yr
- Snowfall
- 0 in/yr
- Heating degree days
- 2,492 (mild)
- Frost-free season
- Jan 28 to Dec 12
How far help isstraight-line
- Hospital
Contra Costa Regional Medical Center - 17.4 mi
- Fire station
Fairfield Fire Department Station 39 - 3.3 mi
- Hardware store
Foster Lumber Yard - 0.8 mi
- Grocery
Grocery Outlet - 0.8 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 94585).
Size a solar systemHeat loss & insulationFirewood per winterRainwater harvestGarden sizePanel tilt
Looking at a specific parcel in Solano 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.