Off-grid site report
Mendocino County, CA
39.3114, -123.7940 · 220 ft elevationRead this before you act on anything below. This is my researched starting point for Mendocino 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 rulesMendocino County, CA
Zoning & raw-land occupancy
Varies locallyMendocino County administers zoning countywide through Planning & Building Services, split into Inland, Coastal, and Town of Mendocino divisions; rules depend on which applies to your parcel. source
Dwellings, tiny homes & RVs
RestrictedStandard state building code applies, but the county offers a 'Class K' alternative construction standard for owner-built rural dwellings on one-acre-plus lots. Tiny home/RV classification specifics are not confirmed; ask the Building Division. source
Building permits & codes
RestrictedThe Building Division enforces state and local building codes, requiring plot plans showing setbacks and septic locations for most permits. source
Septic & composting toilets
RestrictedThe county's Local Agency Management Program (LAMP), approved by the Regional Water Board, sets minimum lot sizes (around a 'Mendocino Acre') and prohibits septic development in certain problem areas like parts of Ukiah/Meadowbrook Valley and Laytonville. Environmental Health issues septic permits and owners must track their own renewal status. source
Greywater reuse
Generally allowedMendocino County Environmental Health has its own greywater guidance and permit process beyond the state baseline, but greywater use does not replace the requirement for a septic system or sewer connection. source
Rainwater harvesting
Generally allowedNo county-specific restriction was found; the state's general rainwater capture framework appears to govern.
Private wells & water rights
RestrictedEnvironmental Health, along with Planning & Building and sometimes the Coastal Commission, issues well permits under the county's own well ordinance for construction, repair, or alteration. source
Living disconnected from utilities
Unclear - verifyNo standalone county ordinance addressing off-grid utility disconnection was found; it appears to be governed indirectly through septic and well permitting tied to building permits. Confirm with Building and Environmental Health directly.
Sun30-year normals
- Peak-sun hours, annual average
- 5.0 hrs/day
- Worst month (sizes an off-grid array)
- 3.3 hrs/day
- Yearly output per 1 kW of panels
- 1,409 kWh
JFMAMJJASOND
Weather1991-2020
- Precipitation
- 43 in/yr
- Snowfall
- 0 in/yr
- Heating degree days
- 4,945 (moderate)
- Frost-free season
- Mar 2 to Dec 7
How far help isstraight-line
- Hospital
Mendocino Coast District Hospital - 8.3 mi
- Fire station
Mendocino Volunteer Fire Dept. - 0.4 mi
- Hardware store
Mendocino Hardware - 0.3 mi
- Grocery
Harvest Market at Mendosa's - 0.4 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 95460).
Size a solar systemHeat loss & insulationFirewood per winterRainwater harvestGarden sizePanel tilt
Looking at a specific parcel in Mendocino 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.