Unincorporated Boone County, Illinois requires building permits and applies its zoning ordinance to land outside municipalities12. The Building & Zoning Department reviews construction under adopted county codes, while the Health Department handles private septic and well permits34. Septic plans and well applications must be approved before the county releases a building permit5.
At a glance
- Building permit
- Required for most construction in unincorporated Boone County1
- Zoning
- County ordinance applies in unincorporated Boone County2
- Septic
- County Health Department permit and inspections required46
- RV / tiny home
- No rule confirmed; check the zoning district's use table for your parcel first7
- Private well
- Permit required before drilling and before release of the building permit5
- Manufactured/mobile home
- Allowed statewide if installed to Illinois code; local zoning, building and floodplain rules still apply8
- Setbacks & height
- Set by zoning district, not one countywide number910
Who to call
Building permits
Boone County Building & Zoning Department
Building permits and inspections for unincorporated Boone County under its adopted codes
1212 Logan Avenue, Suite 101
Zoning
Boone County Planning Department
Zoning administration, zoning verification letters and lot-of-record determinations for unincorporated Boone County
1212 Logan Ave., Suite 102, Belvidere, IL 61008
Septic permits
Boone County Health Department - Environmental Center
Septic (private sewage disposal) and well permits, soil bores, and installation inspections for unincorporated Boone County
1212 Logan Ave., Suite 102, Belvidere, IL 61008
Roads & driveways
Boone County Highway Department
County road maintenance and construction, including Boone County Highway Access Permits for driveways onto county roads
9759 IL Route 76
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 Boone County, Illinois?
Unincorporated Boone County, Illinois requires a building permit for most new construction1. The Boone County Building & Zoning Department administers the county's adopted building, residential, mechanical, fuel-gas, energy, electrical and plumbing codes3. Most structures also need Health Department site-plan approval before the county releases the building permit11. Illinois does not issue building permits or perform building-code inspections for privately funded construction; those requirements are handled by the applicable local government1213. A property inside a municipality may follow that municipality's process, so confirm jurisdiction before applying.
Who is the Boone County building department, and how do you reach them?
Boone County's Building & Zoning Department is the building department for unincorporated Boone County14. Reach it at 815.544.6176 or [email protected], at 1212 Logan Avenue, Suite 101 in Belvidere, Monday through Friday, 8:00 a.m. to 4:30 p.m.14. Building applications go through CloudPermit; after review, the applicant is told whether the submission complies, and the permit is released after approval and payment11. Missing information can delay that review11. For zoning verification and lot-of-record questions, call the Planning Department at 815-547-669815. Septic and private-well permits go to the Health Department - Environmental Center at (815) 544-2951, extension 2164.
Does Boone County have zoning?
The Boone County Zoning Ordinance applies to the unincorporated portion of Boone County and regulates land uses, development intensity and setback lines by district2. The county tells applicants to confirm a property's zoning with the Planning Department before starting a septic, well, building or zoning application because proper zoning is required for a building permit16. A zoning verification letter from the Planning Department costs $50, while a lot-of-record determination costs $7515. Properties in subdivisions may need additional approvals or permits, so check the association's requirements as well as county zoning before designing the project17.
How do septic permits work in Boone County?
Private septic systems in Boone County go through the Boone County Health Department - Environmental Center and must meet both state and county private sewage disposal codes4. Installation must be completed by an installer licensed by Illinois and Boone County, except that an unlicensed homeowner installer follows the county's additional-inspection process46. Notify the Health Department 48 hours before installation, schedule the final inspection, and leave every part of the system uncovered until the health officer has inspected and approved it6. An unlicensed homeowner installer must pay for two additional compliance inspections6. The septic plan and any private-well application must be approved, with permits issued, before installation or drilling begins and before the county releases a building permit5.
Can you live in an RV or tiny home on your land in Boone County?
No Boone County page states a rule specifically for keeping an RV or tiny home on your own unincorporated land, and that gap is unconfirmed, not a green light7. Because Boone County zones the entire unincorporated county, any RV or tiny-home use still falls under the applicable zoning district's rules, so confirm with the Planning Department at 815-547-6698 or get a zoning verification letter for your specific parcel before you place one157. If you plan to live in a manufactured or mobile home instead, Illinois law allows occupancy statewide, but a moved home must be secured with equipment meeting Illinois Department of Public Health standards, and since December 31, 2001, installation must be done by an Illinois-licensed installer or according to the manufacturer's instructions8. Local zoning, building and floodplain requirements still apply on top of that state installation rule8. For off-grid sanitation, Illinois approves privies, portable toilets, recirculating toilets, incinerator toilets and compost toilets for human waste, though other domestic wastewater still needs a conventional private sewage disposal system18.
Building a home in Boone County: the steps, in order
- Confirm the parcel's zoning with the Boone County Planning Department; proper zoning is required before a building permit can issue16.
- If the parcel is in a subdivision, ask the association about additional approvals or permits17.
- Submit the septic plan and private-well application, when needed, to the Health Department; both permits must issue before installation or drilling and before release of the building permit5.
- Submit the building application through CloudPermit with complete plans; missing information can delay review11.
- After approval, pay the required amount so the Building & Zoning Department can release the permit11.
- Give the Health Department 48 hours' notice before septic installation and leave the system uncovered until inspection and approval6.
- Ask the Boone County Highway Department about access if the driveway meets a county road; the department lists Boone County Highway Access Permits19.
What to check before you buy land in Boone County
Only about 24.9% of Boone County soils avoid severe limits for a conventional septic drain field, so make septic feasibility an early contingency rather than assuming a standard system will work20. About 99.8% of county land is at a 15% slope or less, while about 9.7% is wooded2122. The effective property-tax rate is about 2.3%, and the median annual bill is about $4,5072324. Before closing, verify zoning and lot-of-record status with Planning, confirm septic and well feasibility with the Health Department, and ask the association about extra approvals if the land lies in a subdivision15417.
Watch-outs
- We could not confirm a general owner-builder exemption from Boone County's building-permit requirements; ask the Building & Zoning Department at 815.544.6176 before planning to act as your own contractor2514.
- No Boone County page addresses RV or tiny-home living on your own land directly; get a zoning verification letter from the Planning Department for your specific parcel rather than assuming a use is allowed15.
Sources
- Boone County - Building & Zoning Department (2026 county census)
- Boone County Zoning Information, quoted and re-checked
- Building & Zoning, quoted and re-checked
- Private Sewage Disposal, quoted and re-checked
- Private Sewage Disposal, quoted and re-checked
- Private Sewage Disposal, quoted and re-checked
- Boone County Zoning Information (2026 county census)
- Manufactured & Modular Homes/Mobile 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
- 55 ILCS 5/5-12001 — Authority to regulate and restrict location and use of structures (Illinois statewide rule), quoted and re-checked
- Building & Zoning, quoted and re-checked
- Illinois Codes FAQ (Illinois statewide rule), quoted and re-checked
- Illinois Codes FAQ (Illinois statewide rule), quoted and re-checked
- Boone County Building & Zoning Department (boonecountyil.gov)
- Boone County Planning Department (boonecountyil.gov)
- Boone County Health Department - Environmental Center (boonecountyil.gov)
- Building & Zoning, quoted and re-checked
- 77 Ill. Adm. Code 905.130 Human Waste Disposal (Illinois statewide rule), quoted and re-checked
- Boone County Highway Department (boonecountyil.gov)
- Share of soils without severe limits for a conventional septic drain field (USDA SSURGO): Bolthole Index county data
- Share of land at 15% slope or less: Bolthole Index county data
- Wooded share of land: Bolthole Index county data
- Effective property tax rate: Bolthole Index county data
- Median property tax bill: Bolthole Index county data
- (2026 county census)
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.