Unincorporated Henry County, Illinois requires a building permit to construct, enlarge, alter, repair, move, demolish or change the occupancy of a building or structure1. County zoning also covers all land outside incorporated areas, although agricultural buildings have a limited exemption2. Private septic systems and wells require Health Department permits34.
At a glance
- Building permit
- Required for construction and other listed building work in unincorporated areas1
- Zoning
- Yes, on land outside incorporated areas; a limited agricultural exemption applies2
- Septic / well
- Health Department permits are required for private septic systems and wells34
- Owner-builder exemption
- Not stated on the county's permit instructions; confirm directly with Zoning & Building5
- Agricultural buildings
- Exempt from the building code and from zoning except a minimum road right-of-way setback6
- Manufactured home
- Allowed statewide, with tie-down and licensed-installer requirements plus local zoning rules7
- Driveway access
- A county Highway Department permit is needed for new driveway access in unincorporated Henry County8
Who to call
Building permits
Henry County Zoning & Building Department
Zoning, planning, subdividing, building permits, agricultural areas and floodplain management for unincorporated Henry County
307 West Center Street, Cambridge, IL 61238
Codes & inspections
Henry County Building Permit Instructions (Zoning & Building Department)
The county's published building-permit process, fees, inspections and exemptions under the International Building Code
Septic permits
Henry County Health Department (Environmental Health)
Private sewage disposal (septic) and water-supply (well) permits for Henry County
4424 US Hwy 34, Kewanee, IL
Roads & driveways
Henry County Highway Department
Driveway access permits onto county roads in unincorporated Henry County
Contact details are copied from each office’s official page and were checked against it on September 29, 2026.
Do you need a building permit in Henry County, Illinois?
Yes. Unincorporated Henry County requires a 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 one can bring a stop-work order and fines or penalties up to $5001. Illinois does not issue permits or conduct inspections for privately funded construction; those tasks belong to the local government, while locally adopted codes must meet the applicable statewide structural baseline910. Agricultural buildings may qualify for an exemption from the building code and most zoning rules, but the road-right-of-way setback still applies12. Agricultural structures also remain subject to applicable floodplain rules and required septic or well approvals1134.
Who is the Henry County building department, and how do you reach them?
Henry County Zoning & Building is at 307 West Center Street in Cambridge and can be reached at 309-937-341912. The office handles zoning, planning, subdivision, building, agricultural-area and floodplain programs in unincorporated Henry County1213. Henry County publishes a building-permit application requiring the listed project, property, contractor, plot-plan and construction information before a permit can be issued14. Private septic and well permits run through the Henry County Health Department at 309-852-01971534. A new driveway onto a county road should be coordinated with Henry County Highway at 309-937-33468.
Does Henry County have zoning?
Yes. Henry County zoning covers land outside incorporated areas and regulates land use plus the use and location of buildings and structures2. A plot plan for a new structure or addition must show setback compliance as part of the published application process14. Setback and principal-building height rules depend on the applicable zoning district, so confirm the parcel's district with Zoning & Building before fixing a site plan1617. One concrete county limit applies to accessory buildings: they may not exceed 20 feet from the floor to the roof peak18. Agricultural buildings are exempt from zoning except for the minimum road-right-of-way setback, but floodplain regulations can still apply211. Dividing land also falls under Henry County's subdivision program, so discuss a proposed split with Zoning & Building before relying on a new lot layout13.
How do septic and well permits work in Henry County?
A private sewage-disposal system in unincorporated Henry County requires a Health Department permit, and the county application directs builders to obtain the applicable well or septic approval3. Authority is shared across Henry County Health Department, Illinois Department of Public Health and Illinois Environmental Protection Agency requirements, depending on the system and issue19. Statewide, a new private sewage system needs plan approval from the state or applicable local health authority before construction, and the installer must provide at least 48 hours' notice before starting20. Only about 39.1% of Henry County soils rate as having no severe limitation for a conventional drain field, so make septic feasibility an early site question21. A private well also requires a permit, including for an agricultural project when water-supply approval applies4. We could not confirm the county's septic-inspection sequence or whether a public-system connection is mandatory on any particular parcel; ask Environmental Health before closing or designing the system15.
Can you live in an RV, manufactured home or tiny home on your land in Henry County?
Manufactured homes are allowed statewide as dwellings, but installation comes with rules: a home moved since January 1, 1980 needs tie-down equipment meeting Illinois Department of Public Health standards, and since December 31, 2001 it must be installed by an Illinois-licensed installer, or by the homeowner, following the manufacturer's instructions or the state's Manufactured Home Installation Code7. Local zoning, building, floodplain and utility requirements still apply on top of that, so check with Henry County Zoning & Building before you set one12. RVs are murkier: the only state rule turned up here covers licensed campgrounds, which the state inspects annually, and that isn't the same question as whether you can live in an RV on your own rural parcel22. Treat that as unconfirmed and call Zoning & Building at 309-937-3419 before you plan to live in an RV or tiny home while you build12.
Building a home in Henry County: the steps, in order
- Call Henry County Zoning & Building at 309-937-3419 to confirm the zoning district, setbacks, floodplain status and whether a proposed land split needs subdivision review121311.
- Contact the Henry County Health Department at 309-852-0197 for the required private well or septic permit and site approval1534.
- Ask Henry County Highway about a new driveway onto a county road8.
- Complete every part of the building application, including the owner, contractors, project and occupancy descriptions, legal description, plot plan, plans and specifications14.
- Submit the application and supporting documents to Zoning & Building before work starts114.
- Request the required county inspections as the permitted work progresses14.
What to check before you buy land in Henry County
Ask Zoning & Building for the parcel's zoning district, setbacks and floodplain status before treating it as buildable; even an exempt agricultural structure must follow applicable floodplain rules1211. Only about 39.1% of Henry County soils rate free of severe limitations for a conventional drain field, so have the Health Department assess the site early2115. Confirm that any proposed lot split can comply with the county subdivision program13. Access onto a state-maintained road requires an Illinois Department of Transportation permit before work begins23. Henry County has about 48,448 residents at 58.9 people per square mile; about 96.6% of its land has gentle slope, while 7.4% is wooded24252627. 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%282930.
Watch-outs
- Henry County's own permit instructions don't state an owner-builder exemption from the building permit requirement; confirm directly with Henry County Zoning & Building12 rather than assuming one exists5.
- Whether you can live in an RV on your own rural land in Henry County isn't clearly answered by the state rules found here; the only state rule covers licensed campgrounds, so call Zoning & Building before you rely on an RV during a build2212.
- Private septic systems and wells need Health Department permits even when an agricultural structure qualifies for a building or zoning exemption34.
Sources
- Henry County International Building Code Information and Instructions, quoted and re-checked
- Henry County International Building Code Information and Instructions, quoted and re-checked
- Building Permit Application, quoted and re-checked
- Building Permit Application, quoted and re-checked
- (2026 county census)
- Henry County Building Permit Instructions (Zoning & Building Department) (henrycty.com)
- Manufactured & Modular Homes/Mobile Structures (Illinois statewide rule), quoted and re-checked
- Henry County Highway Department (henrycty.com)
- Illinois Codes FAQ (Illinois statewide rule), quoted and re-checked
- Illinois Codes (Illinois statewide rule), quoted and re-checked
- Application for Agricultural Structure/Building Exemption, quoted and re-checked
- Henry County Zoning & Building Department (henrycty.com)
- Zoning Ordinance For, quoted and re-checked
- Building Permit Application, quoted and re-checked
- Henry County Health Department (Environmental Health) (henrycty.com)
- 55 ILCS 5/5-12001 — Authority to regulate and restrict location and use of structures (Illinois statewide rule), quoted and re-checked
- 55 ILCS 5/5-12001 — Authority to regulate and restrict location and use of structures (Illinois statewide rule), quoted and re-checked
- Zoning Ordinance For, quoted and re-checked
- Zoning Ordinance For, quoted and re-checked
- 77 Ill. Adm. Code 905.190 Installation Approval (Illinois statewide rule), quoted and re-checked
- Share of soils without severe limits for a conventional septic drain field (USDA SSURGO): Bolthole Index county data
- Youth Camps and Campgrounds (Illinois statewide rule), quoted and re-checked
- Highway Permits (Illinois statewide rule), quoted and re-checked
- County population: Bolthole Index county data
- Population density: Bolthole Index county data
- Share of land at 15% slope or less: Bolthole Index county data
- Wooded share of land: Bolthole Index county data
- Typical home value (Zillow): Bolthole Index county data
- Median property tax bill: Bolthole Index county data
- Effective property tax rate: Bolthole Index county data
Written September 29, 2026 from the rules quoted below, each taken from an official source and re-checked by an independent reviewer. This is research, not legal advice: rules change, so confirm with the office before you buy or build.