Building permits, zoning and land rules in Greene County, Illinois

Unincorporated Greene County appears not to require a county residential building permit; ask the County Board to confirm the parcel's current requirements before construction¹. Illinois' statewide building-code requirements took effect in 2025, but Greene County's local code-adoption status remains unconfirmed². Locally adopted residential codes must meet the state's minimum structural requirements; in jurisdictions without a local building code, the residential framework distinguishes projects where purchaser and builder agree on a code from those where they do not². Illinois does not issue building permits, perform code-compliance inspections or issue occupancy permits for privately funded construction; any such approvals come from local government³. New or substantially improved commercial buildings in a non-building-code jurisdiction require a qualified inspector's compliance statement⁷.

Greene County lists no building, zoning or planning department, so start with the County Board to confirm whether an unincorporated project needs any local building, inspection or occupancy approval¹. For zoning in or near Carrollton, ask the city: Carrollton administers its own zoning, and its code reaches outside city limits^4,8. For septic, contact the Greene County Health Department's Division of Environmental Health at its Carrollton office⁹. The Greene County Highway Department is responsible for county highways and bridges and assists townships and municipalities, while township roads are administered separately¹⁰. Ask the Highway Department which road authority controls the frontage before designing an entrance. IDOT requires a permit before driveway or other work begins within a state-maintained road right-of-way⁶.

Greene County appears not to administer countywide zoning for unincorporated land, but no official county source expressly confirms that no zoning ordinance exists¹. Carrollton administers its own zoning, and its code reaches beyond city limits, so nearby unincorporated land may face city zoning^4,8. Septic approval inside Carrollton stays with the Greene County Health Department⁵. We could not confirm county rules for minimum lot size, setbacks, building height, minimum dwelling size, manufactured homes or accessory dwellings. Illinois limits county zoning of land whose principal activity is agriculture, although agricultural buildings may still have to meet building or setback lines and counties may set a minimum lot size for residences on agricultural land¹¹. A qualifying public agricultural experience conducted as a secondary use on a working farm does not require a conditional-use permit, special-use permit, special exception or variance¹².

Every private sewage disposal system in Greene County needs a permit from the Greene County Health Department before installation, and the county's application packet states there was no permit fee at the time of publication⁵. The Health Department must inspect the installation — with at least 48 hours' notice — before it is covered⁵. A person who owns and occupies a personal single-family residence may perform that home's septic work, but work by anyone else must be done by a licensed contractor; this is not a general exemption from building rules⁵. If soil is unsuitable for a standard subsurface seepage field, the county packet allows a sandfilter or aeration system as the alternative⁵. Only about 35% of Greene County's soils are free of severe limitations for a conventional drain field, so arrange a site evaluation early¹³. Illinois regulates septic through IDPH and local health agencies that review plans¹⁴.

We could not confirm a Greene County rule that allows, limits or prohibits long-term RV occupancy, temporary camping or tiny-home occupancy on private land. Ask the County Board about land use and the Greene County Health Department about wastewater before relying on an RV or tiny home as a residence⁹. Illinois' campground licensing rules address regulated campgrounds, not whether one owner may live in an RV on a private parcel¹⁵. State manufactured-home rules likewise address installation and licensed communities, while local zoning, building, floodplain and utility requirements may still apply¹⁶. A private sewage system must be approved by the Greene County Health Department before installation, regardless of the dwelling plan⁵.

1. Confirm whether the parcel is unincorporated and ask the County Board whether local building, inspection or occupancy approval applies^1,3.
2. Ask about zoning at the parcel: Carrollton's zoning reaches outside the city limits, while Greene County's countywide zoning status is unconfirmed^1,4.
3. Confirm the applicable residential code with your designer or builder; local code adoption and purchaser-builder agreement affect the Illinois requirements².
4. Evaluate soils early because only about 35% of Greene County soils lack severe limitations for a conventional drain field¹³.
5. Obtain Greene County Health Department approval before septic installation and arrange the required pre-cover inspection with at least 48 hours' notice^5,9.
6. Identify the road authority; IDOT approval is required before work in a state-road right-of-way^6,10.
7. Check floodplain status with IDNR before siting improvements; regulated floodway construction needs authorization before work, unless a statewide or regional permit already covers the project¹⁷.

Before buying unincorporated land, ask the County Board about building permits, code adoption and occupancy approval, and confirm zoning authority near Carrollton^1,2,3,4. Get a soil evaluation before relying on a conventional drain field: only about 35% of county soils lack severe limitations, and unsuitable soil may call for a sandfilter or aeration system^5,13. Identify the frontage road's authority before planning a driveway; IDOT requires approval for work in a state-road right-of-way^6,10. IDNR requires authorization before regulated floodway construction and generally for floodplain work where no floodway is delineated; qualifying statewide or regional permits may cover a project without an application¹⁷. IDNR's initial determination of whether authorization is required is free with sufficient information; when individual review is required, published standard fees range from $200 to $5,000, are adjusted annually and capped at $5,000¹⁸. A new, modified or sealed private well needs advance approval from IDPH or an approved local health department¹⁹.