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

Yes. Unincorporated Sangamon County requires building permits for listed projects including new construction, additions, alterations, foundations, mobile-home relocations, and accessory structures; some projects also need sub-permits¹. Sangamon County enforces amended adopted building codes for county-administered projects³. Illinois does not issue local permits for privately funded construction, so the applicable county or municipality handles the permit⁹. Sangamon County's published fee schedule, dated December 1, 2025, charges a residential structure permit fee of $0.58 per square foot of living area with a $100 minimum, and $0.08 per square foot each for electrical, HVAC and plumbing permits, also with a $100 minimum¹⁰. A mobile home costs a flat $300 and a modular home a flat $600, each including zoning, electrical, HVAC and plumbing¹⁰. A narrow state exemption lets qualifying owner- or lessee-occupants perform plumbing work on their own single-family residence, but it is not a general exemption from building permits or other construction trades⁷. Sangamon County accepts agricultural-exempt permits, but the published material does not define eligibility or every requirement waived². Ask Building and Zoning to classify a proposed farm structure before relying on that exemption⁸.

The Sangamon County Department of Building and Zoning handles county building permits, inspections, and zoning administration from 200 S. Ninth St., Room 234, Springfield, IL 62701⁸. Call (217) 753-6760 or email zoning@sangamonil.gov during weekday office hours⁸. Applications are fillable and may be emailed to the department, and some projects require sub-permits¹. The department also accepts home-occupation, fence, temporary-use, agricultural-exempt, and building permits⁸. Before filing, tell the department whether the parcel is inside a municipality because municipal zoning requirements may apply separately³.

Yes. Sangamon County administers its zoning ordinance in unincorporated areas and accepts zoning amendments, variances, and conditional-use petitions². The ordinance establishes district boundaries and assigns uses to specific districts, so a use that works on one rural parcel may not work on another¹¹. Incorporated municipalities may impose their own zoning requirements, so land inside a municipality needs confirmation from that municipality³. In the agricultural district the county lists a 30-foot front-yard setback, a 10-foot side-yard setback (15 feet on a corner lot) and a 30-foot rear-yard setback, while agricultural buildings have 0-foot side and rear setbacks¹². An accessory building in a required rear yard may sit 3 feet from a side or rear property line, and a lot must have 20 feet of road frontage¹². The county's chart leaves out maximum building height and some other yard and bulk rules, and we could not confirm a general minimum home size, minimum lot size or lot coverage¹². Ask Building and Zoning for the parcel's district, allowed uses, and the remaining dimensional standards before designing a house, tiny home, accessory dwelling, or parcel split⁸.

Sangamon County requires a permit to install a new septic system or repair or replace an existing system⁴. The owner must hire a licensed septic contractor and a licensed soil scientist; the contractor typically prepares and submits the application to the Sangamon County Health Department⁴. Only about 25% of county soils rate free of severe limits for a conventional drain field, so settle septic feasibility before fixing a house site¹³. Private wells also require a county permit: use a licensed well-pump contractor for work on an existing well and a licensed well-driller for a new or replacement well⁴. Environmental Health works toward approval of submitted well plans within 7–10 business days⁴.

We could not confirm a general rule allowing full-time RV or tiny-home occupancy on private land in unincorporated Sangamon County. The county assigns uses by zoning district and accepts temporary-use permits, but neither fact establishes that residential RV use or a tiny home is allowed on a particular parcel^8,11. Floodplain rules separately treat a travel trailer placed for more than 180 days as development requiring a floodplain permit⁵. Before buying or moving a unit onto land, call Building and Zoning at (217) 753-6760 and ask whether the proposed occupancy is allowed in the parcel's district, whether a temporary-use approval applies, and which building and utility requirements must be met⁸.

1. Ask Building and Zoning whether county or municipal rules control the parcel, then confirm the zoning district, allowed use, and dimensional standards^3,11.
2. If the site lacks sewer service, hire a licensed soil scientist and septic contractor; the contractor typically files the county septic application⁴.
3. For a private well, hire the correct licensed well professional and complete the county well-permit process⁴.
4. Check whether the site is in the floodplain and obtain the required county floodplain-development permit before covered work⁵.
5. Submit the fillable building and zoning applications by email with any required sub-permits¹.
6. For access onto a county highway, contact the Highway Department for the required permit or installation⁶.
7. If dividing land, account for County Engineer approval of public improvements within the county's subdivision jurisdiction⁶.

Before buying, confirm the governing jurisdiction and whether the intended house, tiny home, farm structure, or other use fits the parcel's zoning district^3,11. Do not assume a farm building qualifies for an exemption merely because the county accepts agricultural-exempt permits; eligibility and the scope of relief remain questions for Building and Zoning². Check septic feasibility early because only about 25% of county soils rate free of severe limits for a conventional drain field¹³. Determine whether the homesite is in the floodplain, where covered development requires a separate county permit⁵. Confirm the road authority before planning access because the county rule specifically covers driveways onto county highways⁶. The effective property-tax rate is near 2%, and the median annual bill is about $3,369¹³.