Off-grid site report
LaSalle County, IL
41.5577, -89.1271 · 768 ft elevationRead this before you act on anything below. This is my researched starting point for LaSalle County, IL, 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 rulesLaSalle County, IL
Zoning & raw-land occupancy
Varies locallyLaSalle County has its own countywide zoning ordinance administered by the Land Use Department, but it only applies to unincorporated areas; incorporated towns have separate codes. source
Dwellings, tiny homes & RVs
Unclear - verifyThe county defines manufactured homes and has a Mobile Home Park Ordinance, but no confirmed minimum size for tiny homes or clear rule on RV year-round occupancy was found; ask the Land Use Department. source
Building permits & codes
Varies locallyA building permit is required for residential structures over 200 square feet or larger than 20 feet on any side, per the county Land Use Department; codes reference 2024 International code family and 2023 NEC as of the 2025 update. source
Septic & composting toilets
Generally allowedSeptic systems are permitted through the LaSalle County Health Department's Environmental Health Division, which administers the state's Private Sewage Disposal Code locally; composting toilets aren't separately addressed. source
Greywater reuse
Unclear - verifyNo LaSalle County or state-specific greywater reuse guidance was found; check with the county Health Department directly.
Rainwater harvesting
Unclear - verifyNo county ordinance or health department guidance on rainwater harvesting was found in official sources.
Private wells & water rights
Generally allowedA permit from the LaSalle County Health Department is required before drilling a new well, under the statewide Illinois Water Well Construction Code as locally administered. source
Living disconnected from utilities
Varies locallyNo standalone ordinance addresses grid disconnection, but the county requires approved well and septic systems before issuing an occupancy certificate for a home.
Sun30-year normals
- Peak-sun hours, annual average
- 4.7 hrs/day
- Worst month (sizes an off-grid array)
- 2.8 hrs/day
- Yearly output per 1 kW of panels
- 1,349 kWh
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Weather1991-2020
- Precipitation
- 37 in/yr
- Snowfall
- 30 in/yr
- Heating degree days
- 7,124 (cold)
- Frost-free season
- Apr 28 to Oct 10
How far help isstraight-line
- Hospital
OSF Saint Paul Medical Center - 2.1 mi
- Fire station
Earlville Fire District - 10.9 mi
- Hardware store
Do it Best - 0.3 mi
- Grocery
Sullivans - 0.1 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 61342).
Size a solar systemHeat loss & insulationFirewood per winterRainwater harvestGarden sizePanel tilt
Looking at a specific parcel in LaSalle County, IL?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.