Off-grid site report
Mercer County, WV
37.3104, -81.0276 · 1,978 ft elevationRead this before you act on anything below. This is my researched starting point for Mercer County, WV, 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 rulesMercer County, WV
Zoning & raw-land occupancy
Unclear - verifyNo official Mercer County Commission page describing a countywide zoning ordinance was found. Zoning in West Virginia is optional and locally adopted, so unincorporated parts of the county may have none, while the City of Princeton has its own zoning function. source
Dwellings, tiny homes & RVs
Unclear - verifyNo official Mercer County or City of Princeton page addresses tiny-home or RV occupancy standards specifically. Ask the local building or zoning office directly.
Building permits & codes
Varies locallyMercer County has an adopted floodplain ordinance requiring a compliance certificate before utility connection or occupancy in flood hazard areas. A general countywide building permit requirement outside flood zones was not confirmed, while the City of Princeton runs its own building inspections program for construction inside city limits. source
Septic & composting toilets
Generally allowedThe Mercer County Health Department's Environmental Health division issues septic and sewage disposal permits, operating under West Virginia's statewide sanitation standards. Composting toilets are not addressed on official pages, so confirm directly whether one meets local requirements.
Greywater reuse
RestrictedNo separate Mercer County greywater rule was found; it appears to be folded into the same sewage permitting the county Health Department oversees alongside the state Bureau for Public Health.
Rainwater harvesting
Unclear - verifyNo Mercer County ordinance or health department policy on rainwater collection was found, which generally suggests it is unregulated for non-potable use under the state baseline.
Private wells & water rights
Generally allowedThe Mercer County Health Department's Environmental Health division handles well permitting and guidance, administered under West Virginia's statewide Water Well Certification Program.
Living disconnected from utilities
Unclear - verifyNo county ordinance requiring connection to public utilities was found. The floodplain ordinance only ties utility connection approval to a compliance certificate within mapped flood hazard areas, not a general hookup mandate.
Sun30-year normals
- Peak-sun hours, annual average
- 4.7 hrs/day
- Worst month (sizes an off-grid array)
- 3.2 hrs/day
- Yearly output per 1 kW of panels
- 1,298 kWh
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Weather1991-2020
- Precipitation
- 38 in/yr
- Snowfall
- 29 in/yr
- Heating degree days
- 5,685 (cold)
- Frost-free season
- May 5 to Oct 5
How far help isstraight-line
- Hospital
Princeton Community Hospital - 6.0 mi
- Fire station
East River Fire Department - 4.3 mi
- Hardware store
Lowe's - 4.0 mi
- Grocery
Walmart Supercenter - 3.5 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 24739).
Size a solar systemHeat loss & insulationFirewood per winterRainwater harvestGarden sizePanel tilt
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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.