Off-grid site report
Twin Falls County, ID
42.5559, -114.4701 · 3,750 ft elevationRead this before you act on anything below. This is my researched starting point for Twin Falls County, ID, 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 rulesTwin Falls County, ID
Zoning & raw-land occupancy
RestrictedTwin Falls County has an adopted zoning ordinance (Title 8) administered by the Board of County Commissioners and a Planning & Zoning Commission, so land use and permitted uses are defined by zone rather than left open. Incorporated cities like Twin Falls and Buhl have their own separate zoning codes and impact-area agreements. source
Dwellings, tiny homes & RVs
Varies locallyCounty code defines manufactured/mobile homes specifically (full plumbing/electrical, built for long-term occupancy, arriving complete), and whether an RV or tiny home qualifies as a permanent legal dwelling depends on that definition and the zoning district. Not confirmed whether RVs are allowed as standalone long-term residences outside those definitions; ask County Planning & Zoning. source
Building permits & codes
Generally allowedTwin Falls County has adopted the 2018 International Codes (IBC, IRC, IECC, IMC, IFGC, IEBC, IFC) with Idaho amendments, plus the 2018 Idaho Manufactured Home Installation Standards, enforced by the County Building Department for unincorporated areas. The City of Twin Falls runs a separate building program within city limits. source
Septic & composting toilets
Generally allowedSeptic permitting for Twin Falls County is handled by the South Central Public Health District (SCPHD), not the county directly, and requires fees, site plans, and soil data review before a valid permit is issued. Some county land-use applications also require an SCPHD letter confirming septic suitability. source
Greywater reuse
Unclear - verifyNo Twin Falls County-specific greywater ordinance was found; greywater appears to be handled through the same SCPHD/state DEQ subsurface sewage disposal process as septic. Confirm directly with SCPHD since no distinct county allowance or restriction was identified. source
Rainwater harvesting
Unclear - verifyNo official Twin Falls County or SCPHD page addressing residential rainwater harvesting was found; this likely falls under Idaho's general water law administered by IDWR, but no county ordinance was identified either way.
Private wells & water rights
Generally allowedWell drilling permits are issued by the Idaho Department of Water Resources (state level), not the county, and domestic wells generally don't need the extra water-rights approvals required for irrigation or commercial wells. IDWR's Southern Region office is located in Twin Falls. source
Living disconnected from utilities
Unclear - verifyNo specific Twin Falls County ordinance was found that explicitly permits or bans living without utility hookups; building, septic, and well permits still apply where triggered, but no standalone utility-connection mandate was identified in county code searches.
Sun30-year normals
- Peak-sun hours, annual average
- 5.4 hrs/day
- Worst month (sizes an off-grid array)
- 3.0 hrs/day
- Yearly output per 1 kW of panels
- 1,538 kWh
JFMAMJJASOND
Weather1991-2020
- Precipitation
- 10 in/yr
- Snowfall
- 13 in/yr
- Heating degree days
- 5,888 (cold)
- Frost-free season
- May 4 to Oct 3
How far help isstraight-line
- Hospital
St. Luke's Magic Valley Regional Medical Center - 2.7 mi
- Fire station
Twin Falls Fire Department Station 2 - 2.2 mi
- Hardware store
Krengels Hardware - 0.5 mi
- Grocery
Swensen's - 0.7 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 83301).
Size a solar systemHeat loss & insulationFirewood per winterRainwater harvestGarden sizePanel tilt
Looking at a specific parcel in Twin Falls County, ID?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 21, 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.