Off-grid site report
Grundy County, IL
41.4098, -88.4209 · 551 ft elevationRead this before you act on anything below. This is my researched starting point for Grundy 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 rulesGrundy County, IL
Zoning & raw-land occupancy
Varies locallyGrundy County has adopted a full Unified Development Code governing unincorporated land, administered by the county's Land Use/Planning & Zoning Department, aimed at preserving rural and agricultural character. Incorporated towns like Morris, Coal City, and Minooka set their own separate zoning that controls inside city limits. source
Dwellings, tiny homes & RVs
Unclear - verifyNo official Grundy County text specifically addresses RV residency or tiny-home minimum sizes; manufactured/modular homes are touched by state IDPH standards. Confirm directly with the county Planning & Zoning Office for a site-specific answer. source
Building permits & codes
RestrictedThe county Building Office administers building permits in unincorporated areas under state statute, and even agriculturally exempt structures require a zoning compliance review from the Land Use Department. source
Septic & composting toilets
Generally allowedThe Grundy County Health Department's Environmental Health division issues private sewage disposal permits and enforces siting rules such as distance from bedrock and from streams; licensed installers are generally required, with an exception for homeowners installing systems for their own single-family residence. Composting toilets aren't separately addressed and likely fall under the state's general private sewage rules. source
Greywater reuse
Unclear - verifyNo official county ordinance specifically addresses greywater reuse; because county code closely tracks state IDPH private sewage rules, greywater may be treated as sewage requiring a permitted disposal system. Ask the Environmental Health division directly.
Rainwater harvesting
Unclear - verifyNo official county or state rule specifically authorizing or restricting residential rainwater harvesting was found in this research.
Private wells & water rights
Generally allowedGrundy County has formally adopted the Illinois water well construction and pump installation codes, and the county Health Department issues well construction permits with required setbacks from septic components. source
Living disconnected from utilities
Unclear - verifyNo specific county ordinance was found prohibiting or explicitly permitting disconnection from grid electricity or municipal water/sewer; this appears to inherit the state's unclear status and is governed indirectly through zoning, building, and health permitting.
Sun30-year normals
- Peak-sun hours, annual average
- 4.6 hrs/day
- Worst month (sizes an off-grid array)
- 3.1 hrs/day
- Yearly output per 1 kW of panels
- 1,349 kWh
JFMAMJJASOND
Weather1991-2020
- Precipitation
- 38 in/yr
- Snowfall
- 24 in/yr
- Heating degree days
- 6,156 (cold)
- Frost-free season
- Apr 20 to Oct 19
How far help isstraight-line
- Hospital
Morris Hospital - 2.8 mi
- Fire station
Minooka Fire Protection Dist. - 7.8 mi
- Hardware store
Menards - 1.5 mi
- Grocery
ALDI - 1.6 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 60450).
Size a solar systemHeat loss & insulationFirewood per winterRainwater harvestGarden sizePanel tilt
Looking at a specific parcel in Grundy 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.