Building permits, zoning and septic rules across Illinois counties

At a glance

Residential building permits

20 counties require none; 23 require them in some cases; 59 require them.¹⁶⁷

Countywide zoning

23 counties have none; 65 have zoning; 14 remain unconfirmed.²⁸⁹

No building permit and no zoning

19 counties combine both answers for unincorporated land.¹⁰

Septic approval

IDPH or the applicable local authority must approve plans before construction.³

RV living

36 counties have an answer: 9 allowed, 5 temporary-only, 16 limited, 6 prohibited.⁴

Tiny homes

23 counties have an answer: 11 allowed and 12 limited.⁵

Owner-builder

Qualifying owner occupants may do their own plumbing; code compliance and inspection still apply.¹¹

Water wells

Construction, modification and sealing require a permit from IDPH or an approved local health department.¹²

Who to call

Contact details are copied from each office’s official page and were checked against it on October 10, 2026.

Which Illinois counties don't require a building permit?

Illinois has 20 counties that do not require a residential building permit in unincorporated areas, including Brown County, Schuyler County, Crawford County, Clark County, Clay County, Wayne County, Greene County, Effingham County.¹ Another 23 counties require a building permit only in some cases, while 59 require a residential building permit.⁶⁷ Use the Illinois no-building-codes county list to compare counties by their building-permit answers.¹

Illinois's statewide building-code baseline took effect in 2025, including requirements for jurisdictions without adopted local codes, so the absence of a county building permit does not remove the applicable state code requirements.¹³ The State does not issue building permits for privately funded construction; any required building permit comes through the local government.¹⁴ CDB's Building Codes and Regulations office provides local code directories; ask the local code official which requirements apply to the proposed home.¹⁵

Which Illinois counties have no zoning?

Illinois has 23 counties without countywide zoning, including Brown County, Schuyler County, Crawford County, Clark County, Clay County, Wayne County, Greene County, Richland County.² Countywide zoning is present in 65 counties, and we could not confirm the zoning answer in 14 counties.⁸⁹ Compare the Illinois counties with no zoning before choosing a parcel.²

Illinois has 19 counties combining no residential building permit with no countywide zoning; the combined county list helps narrow that search.¹⁰ Where county zoning applies, setback distances depend on the applicable district or local ordinance, and agricultural buildings may still have to meet setback lines.¹⁶ Even in a county without zoning, a new private sewage disposal system needs plan approval before construction.³

Who issues septic permits in Illinois?

Illinois septic authority is divided among county offices in 74 counties, multi-county health districts in 26, and the state agency in 2; Southern Seven Health Department is the most frequently named district authority.¹⁷ IDPH regulates private sewage disposal and reviews plans alongside local health agencies.¹⁸

Before building a new septic system, obtain plan approval from IDPH or the applicable local authority and submit site information, bedroom count or design volume, and soil or percolation information.³ Notify that authority at least 48 hours before installation, repair or modification begins.³ Ask the health authority serving the parcel for its septic application and fee before ordering equipment.¹⁸

Illinois permits specified human-waste alternatives, including compost and incinerator toilets, but other domestic wastes still require conventional private sewage disposal under that rule.¹⁹ Eligible surface-discharging systems also face Illinois EPA permit conditions, including periodic inspection, monitoring and reporting.²⁰

Can you live in an RV or tiny home on your land in Illinois?

Illinois RV occupancy has an answer in 36 counties: 9 allowed, 5 temporary-only, 16 limited and 6 prohibited; the other 66 are unconfirmed.⁴ The first counties with an allowed county-zoning answer are Richland County, Effingham County, Hancock County; these answers concern county zoning and do not waive sanitation or other applicable requirements.⁴ Browse the Illinois RV-living county list for those county-specific conditions.⁴

Illinois tiny-home occupancy has an answer in 23 counties: 11 allowed and 12 limited, with 79 unconfirmed.⁵ The first allowed entries are Schuyler County, Richland County, Effingham County, with the stated allowances limited to county land-use zoning.⁵ Use the Illinois tiny-home county list and ask the parcel's local building and zoning office about the proposed unit and occupancy.⁵ Illinois's campground law addresses overnight camping in regulated campgrounds; that scope does not establish permission to reside in an RV on a private residential parcel.²¹

Where are the best Illinois counties for a bolthole?

The highest Bolthole Index scores belong to Brown County, Schuyler County, Crawford County, Clark County, Clay County, Wayne County, Fulton County, Greene County.²² Brown and Schuyler lead at 83 out of 100; both have no residential building permit and no countywide zoning, with septic authority at the county level.²² Fulton differs: its building-permit requirement is limited to some cases, county zoning applies, and septic authority is a health district.²²

The median county farmland value across Illinois is $8,250 per acre, while Pope County has the lowest listed value at $4,224 per acre; these are farmland values rather than an asking price for a particular homesite.²³ The median county effective property-tax rate is 1.8%, and the median county property-tax bill is $2,363 annually; neither figure is a parcel-specific tax estimate.²⁴ Compare the county's building, zoning and septic answers alongside land cost when selecting a place to investigate.²²²³

What water-well and owner-builder rules apply in Illinois?

Illinois requires a permit from IDPH or an approved local health department before constructing, modifying or sealing a water well.¹² Water-well permit fees may not exceed $100, and the permit becomes void if construction has not begun within a year of issuance.¹² The application includes well location and distances to contamination sources such as septic tanks and seepage fields, so plan the well and sewage layout together before work starts.¹²

The northeastern Illinois deep bedrock aquifer is identified as declining or over-appropriated in Will County, Kendall County and Kane County.²⁵

Qualifying owner occupants can perform plumbing on a single-family residence intended for their own occupancy, subject to state plumbing standards, inspection and restrictions on hired assistance.¹¹ Local plumbing permits may still be required; the owner-occupant provision does not establish a general exemption from building permits.²⁶

Watch-outs

• The county building-permit counts describe unincorporated land; confirm the address with the city, village or county code official before applying inside municipal limits.¹¹⁵
• A county without a residential building permit still falls under the applicable Illinois building-code baseline and septic plan-approval requirements.¹³³
• Illinois floodway construction can require IDNR authorization, and work in state-highway right-of-way, including driveway access, requires an IDOT permit before work begins.²⁷²⁸
• Counties can adopt or amend building codes; reconfirm the current code with the local code official before finalizing plans.¹⁵

Sources

1. Bolthole Index county rulebook, 102 Illinois counties, as of October 15, 2026: Illinois counties that do not require a residential building permit in unincorporated areas
2. Bolthole Index county rulebook, 102 Illinois counties, as of October 15, 2026: Illinois counties with no county-wide zoning
3. Illinois: 77 Ill. Adm. Code 905.190 Installation Approval, quoted and re-checked
4. Bolthole Index county rulebook, 102 Illinois counties, as of October 15, 2026: Illinois counties' answers on living in an RV on your own land
5. Bolthole Index county rulebook, 102 Illinois counties, as of October 15, 2026: Illinois counties' answers on living in a tiny home on your own land
6. Bolthole Index county rulebook, 102 Illinois counties, as of October 15, 2026: Illinois counties that require a residential building permit only in some cases (for example floodplain or certain structures)
7. Bolthole Index county rulebook, 102 Illinois counties, as of October 15, 2026: Illinois counties that require a residential building permit in unincorporated areas
8. Bolthole Index county rulebook, 102 Illinois counties, as of October 15, 2026: Illinois counties with county zoning
9. Bolthole Index county rulebook, 102 Illinois counties, as of October 15, 2026: Illinois counties whose building-permit or zoning answer we could not confirm
10. Bolthole Index county rulebook, 102 Illinois counties, as of October 15, 2026: Illinois counties with neither a residential building permit nor county-wide zoning
11. Illinois: HB5913 Enrolled — Illinois Plumbing License Law amendment, quoted and re-checked
12. Illinois: 77 Ill. Admin. Code 920.130, Water Well Permit Requirements, quoted and re-checked
13. Illinois: Illinois Codes, quoted and re-checked
14. Illinois: Illinois Codes FAQ, quoted and re-checked
15. Illinois Capital Development Board — Building Codes and Regulations (cdb.illinois.gov)
16. Illinois: ilga.gov, quoted and re-checked
17. Bolthole Index county rulebook, 102 Illinois counties, as of October 15, 2026: Who issues septic permits across Illinois's counties: a state agency, a multi-county health district, or the county
18. Illinois: Private Sewage Disposal, quoted and re-checked
19. Illinois: 77 Ill. Adm. Code 905.130 Human Waste Disposal, quoted and re-checked
20. Illinois: Illinois Surface Discharge Permit (ILG62), quoted and re-checked
21. Illinois: Youth Camps and Campgrounds, quoted and re-checked
22. Bolthole Index county rulebook, 102 Illinois counties, as of October 15, 2026: The 8 highest-scoring Illinois counties on the Bolthole Index (off-grid and homestead land score out of 100), with each one's building-permit, zoning and septic answers
23. Bolthole Index county rulebook, 102 Illinois counties, as of October 15, 2026: Median farmland value per acre across Illinois's counties (USDA census, the middle county's value; USD/acre), with the five least expensive counties
24. Bolthole Index county rulebook, 102 Illinois counties, as of October 15, 2026: Median of Illinois's county effective property tax rates and median county property tax bills
25. Illinois water rights and groundwater management: National Agricultural Law Center and Bolthole Index groundwater review
26. Illinois: 225 ILCS 320/18 — Local regulation; Department standards, quoted and re-checked
27. Illinois: Permit Program, quoted and re-checked
28. Illinois: Highway Permits, quoted and re-checked

Written October 10, 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.