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

Unincorporated Henry County requires a building permit before an owner or authorized agent constructs, enlarges, alters, repairs, moves, demolishes or changes the occupancy of a building or structure¹. Starting work without a building permit can bring a stop-work order and fines or penalties up to $500¹. Henry County’s published instructions identify the International Building Code 2000 Edition; ask Zoning & Building which codes govern your project under Illinois’s statewide baseline effective in 2025^1,2,7. An owner may act as contractor, but building-permit, zoning, code and inspection requirements still apply¹. Qualifying agricultural buildings and structures are exempt from building-code regulations, while road setbacks and floodplain rules remain⁶. Inside Annawan, the town handles building permits for home alterations and other listed structures; private septic systems remain with the local Health Department under IDPH regulation^3,4.

Henry County Zoning & Building is at 307 West Center Street in Cambridge and can be reached at 309-937-3419². The office handles building, zoning, subdivision, agricultural-area and floodplain programs in unincorporated Henry County². The building-permit application needs owner and contractor details, a work and legal description, proposed occupancy and construction documents; new structures and additions also need a plot plan showing setback compliance¹. Health Department plot-plan approval is required before the building permit can be issued, and the fee payable to Henry County Treasurer must accompany the application and construction documents¹. Permitted work requires inspections, including setbacks, footing or foundation and framing; give the building official at least 24 hours’ notice and wait for approval before proceeding past an inspection point¹. Obtain a certificate of occupancy from the Zoning Enforcing Officer before occupying the completed building or addition⁶.

Henry County zoning applies to unincorporated land; incorporated municipalities are outside the county ordinance⁶. Annawan has its own zoning, while private septic systems remain under the local Health Department and IDPH^3,4. Minimum lot size is 43,560 square feet in AG-1/R-1/M-1, 15,000 in AG-2/R-2/B-1, 12,000 in CO-1/HI-1/R-3/R-5 and 3,600 in R-4, subject to applicable exemptions⁶. Minimum ground-floor dwelling area is 825 square feet in AG-1/R-1/M-1/AG-2/R-2/B-1 and 600 in CO-1/HI-1/R-3/R-5/R-4, subject to applicable exemptions⁶. District yard requirements also apply; road setbacks generally measure 40 feet from the common right-of-way/property-line boundary on township/private roads and 50 feet on county, state or federal highways⁶. The application also lists road-centerline distances of 73 feet for township roads and 100 feet for county, state or federal roads⁵. Accessory buildings cannot exceed 20 feet from floor to roof peak; lot-coverage limits vary by district⁶. Ask Zoning & Building to identify the parcel’s district and applicable yard and road setbacks before drawing the site plan^2,6.

The Henry & Stark County Health Department regulates local private septic systems and permits repairs and new installations; IDPH regulates installation statewide⁴. Contact Environmental Health at 309-852-0197 during preliminary planning for private septic and well permits^1,5. Health Department plot-plan approval is needed before the county building permit is issued, and required well and septic permits must be obtained before starting the project¹. A new private sewage system needs IDPH or applicable local-authority plan approval before construction, with at least 48 hours’ notice before work begins⁸. About 39.1% of Henry County soils are rated “not limited” for a conventional drain field; that countywide rating does not establish parcel feasibility, so request a site evaluation early^1,9. We could not confirm the local septic-inspection sequence, public-system connection requirements or approval of alternative off-grid sanitation; ask Environmental Health before designing the system¹.

In Henry County's CO-1 Conservation District, travel- or camping-trailer occupancy is a special use limited to 30 days in a calendar year, and mobile homes are excluded from that provision⁶. Seasonal camps and campgrounds in CO-1 carry the same 30-day occupancy limit, while permanent seasonal cabins must meet R-3 District requirements⁶. Those CO-1 rules do not establish the treatment of an RV in every other zoning district, so ask Zoning & Building about the specific parcel before relying on an RV during construction^2,6. We could not confirm a separate tiny-home occupancy rule; ask Zoning & Building how a proposed tiny home fits the parcel’s district and dwelling requirements². District minimum ground-floor dwelling areas are 600 or 825 square feet, subject to applicable exemptions⁶.

Confirm the zoning district, lot size, setbacks and floodplain status with Zoning & Building before preparing the application^2,6,10. Obtain Health Department plot-plan approval and required well or septic permits, and arrange the driveway-access permit with the highway authority that has jurisdiction; the entrance must be installed before construction starts^1,5. Submit the signed building-permit application, construction documents and fee before starting building work¹. Give at least 24 hours’ notice for required building inspections and wait for approval at each inspection point, then obtain the certificate of occupancy before occupying the building^1,6.

Ask Henry County Zoning & Building whether the proposed home and any lot split comply with the parcel’s district and subdivision requirements^2,6,11. Agricultural land uses and buildings remain subject to floodplain regulations for development, depositing and excavation; ask the department which approvals the parcel needs^2,6,10. The typical home value is about $173,514, with a median property-tax bill near $2,877 a year and an effective rate around 2%⁹.