Bolthole Index

St. Clair County, Illinois

Building permits, zoning and septic rules in St. Clair County, Illinois

41Index Score / 100
#90 of 102 in Illinois

Unincorporated St. Clair County, Illinois requires building permits, inspections and a certificate of occupancy for regulated residential work123. County zoning approval covers unincorporated land and municipalities without their own zoning4. Inside cities with their own codes, ask the city; septic permits still come from the St. Clair County Health Department5.

At a glance

Building permit
Required for regulated construction in unincorporated St. Clair County; listed minor work is exempt1
Zoning
Yes — county rules cover unincorporated land and municipalities without their own zoning, except Scott Air Force Base4
Septic permit
Required through the St. Clair County Health Department before construction or repair6
Private well
A permit and licensed Illinois well driller are required for a new or renovated well7
Base building permit fee
$500 for a single-family home up to 2,500 sq ft, $700 above that, plus a $30 application fee8
Septic permit fee
$300 application fee for a new or repaired private sewage system9
Agricultural buildings
Qualifying agricultural work is fee-free but must still meet setback lines10
Median property tax bill
About $3,533 a year at an effective rate near 2.1%1112

Who to call

Zoning

St. Clair County Building & Zoning Department

Zoning enforcement, zoning compliance certificates, building/electrical/occupancy permits, flood zone determinations and inspections for unincorporated St. Clair County

618-825-2528

zoning@co.st-clair.il.us

10 Public Square, Belleville, IL 62220

Building permits

St. Clair County Building & Zoning Department – Building Permits

Residential and commercial building permit applications, fees and inspection scheduling for unincorporated St. Clair County

Septic permits

St. Clair County Health Department – Water & Private Sewage

Private sewage disposal (septic) permitting, contractor licensing, subdivision review and complaint investigation for St. Clair County

618-233-7769

scchdinfo@co.st-clair.il.us

19 Public Square, Suite 150, Belleville, IL 62220

Contact details are copied from each office’s official page and were checked against it on October 9, 2026.

Off-grid gear

Going off-grid in St. Clair County means bringing your own water and power. The kit we’d start with:

These are affiliate links — we may earn a commission, at no cost to you. As an Amazon Associate, Bolthole Index earns from qualifying purchases.

Do you need a building permit in St. Clair County, Illinois?

Yes. In unincorporated St. Clair County, an owner or authorized agent must obtain a permit before constructing, enlarging, altering, repairing, moving or demolishing a regulated building, changing its occupancy, or doing regulated electrical, gas, mechanical or plumbing work13. Listed exemptions include sidewalks, driveways, concrete patios, siding and replacement windows or doors, but the exemptions do not cover every repair13. St. Clair County has partly adopted the 2012 International Building Code and 2012 International Residential Code with local changes1415. Permitted work must remain accessible, and the permit holder must request inspection before work advances past each inspection point2. A new building cannot be used or occupied until the building official issues a certificate of occupancy; a temporary certificate may be available for a safe portion of an unfinished project3.

Who is the St. Clair County building department, and how do you reach them?

St. Clair County Building & Zoning Department is on the 5th floor of the county building at 10 Public Square in Belleville16. The department handles building, electrical and occupancy permits, zoning, flood-zone determinations, and building and occupancy inspections16. Before applying, obtain an assigned property address from the 9-1-1 Coordinating Office8. Apply to the building official with any required construction documents, pay the applicable fees before issuance, post the permit, and request inspections before successive work is covered17. East Carondelet, Fayetteville, Freeburg, Lenzburg, Marissa, Millstadt, New Athens and St. Libory contract with St. Clair County for building inspections8. Inside another municipality, ask that municipality which office issues permits because the county requirement described here applies to unincorporated St. Clair County13.

Does St. Clair County, Illinois have zoning?

Yes. St. Clair County zoning applies to unincorporated land and municipalities without their own zoning, but excludes property occupied by Scott Air Force Base4. The published districts carry their own use, lot, yard, coverage and height standards, so identify the parcel's district before choosing a house site18. Minimum lot area ranges from examples such as 40 acres in A to 10,000 square feet in SR-319. Front, side and rear setbacks vary by district and include exceptions in the table notes20. The general principal-building height limit is 35 feet, although governmental structures may reach 100 feet and other special rules may apply21. Qualifying agricultural buildings remain subject to setback lines, and a residence or building not used exclusively for agriculture still needs a building permit10. The county's published zoning-compliance letter fee is $3016.

How do septic permits work in St. Clair County, Illinois?

St. Clair County Health Department administers the private-sewage program, and the county code incorporates Illinois licensing and disposal rules5. Obtain a county permit before constructing, altering or extending an individual domestic sewage system; the fee is $300, and routine tank-cover replacement, cleaning and inlet or outlet rodding are exempt from that construction permit22. The permit may be issued to a homeowner or a St. Clair County-licensed private-sewage installer22. State rules also require plan approval before construction and at least 48 hours' notice before installation, repair or modification begins23. Only 10.1% of St. Clair County soils rate without severe limits for a conventional drain field, making site and soil evaluation especially important24. The Health Department must refuse a private-system permit when a sanitary sewer is available within 300 feet for a single-family property or 1,000 feet for specified commercial, multifamily or subdivision projects22.

Can you live in an RV, tiny home or manufactured home on your land in St. Clair County?

We could not confirm that St. Clair County allows long-term RV living or tiny-home occupancy on private land; ask Building & Zoning about the parcel's district and proposed use before buying16. County zoning treats a private recreational area or nonprofit camp as a special use where that provision applies, so temporary camping is not automatically allowed by that rule25. Manufactured homes are limited by zoning district and local siting rules: the MHP district is intended for permanent occupancy in manufactured-home parks, and manufactured housing is prohibited in the AO-3 Installation Buffer26. A county permit for a manufactured or modular home is $150, or $300 when placed over a basement27. Illinois permits certain privies and specialized toilets for human waste, but other household wastewater must still go to a conventional private sewage system28. In county-zoned areas using individual water or sewage, the Health Department must approve facility locations29.

How do you build a home in St. Clair County, step by step?

  1. Obtain the parcel's assigned address from the county's 9-1-1 Coordinating Office8.
  2. Confirm the zoning district, allowed use, lot area, setbacks, lot coverage and height rules with Building & Zoning1819203021.
  3. If public water or sewer is unavailable, obtain Health Department approval for private facilities; a septic permit is $300 and a new or renovated well permit is $200227.
  4. Submit the building application and required construction documents, then pay the applicable fees before issuance1727.
  5. Post the permit and request inspections before covering each successive stage of work217.
  6. Obtain the building official's release before connecting utility, energy, fuel or power service; the official may authorize a temporary connection31.
  7. Complete final inspection and obtain a certificate of occupancy before using the building3.

What should you check before you buy land in St. Clair County?

First confirm whether the parcel is unincorporated or inside a municipality, because the county building and zoning rules described here apply to the county jurisdiction413. Check the zoning district, legal access and flood status before choosing a building site183233. Land abutting a designated Major Area Service Highway needs written Special Highway Access Permit approval from the County Highway Engineer before grading or building-permit issuance32. Work in a flood-hazard area requires lowest-floor elevation documentation before final inspection33. Dividing unincorporated land requires an approved plat before recording; preliminary review costs $40 per lot or tract with a $300 minimum, and final review costs $25 per lot or tract with a $100 minimum34. The nearest city of 100,000 or more is about 19 miles from the county center35. Test soils before assuming a standard septic field will work because only 10.1% of county soils rate without severe limits for a conventional drain field24.

Watch-outs

  • St. Clair County issues permits free of charge for qualifying agricultural construction, but agricultural buildings must still meet setback lines and a residence or nonexclusive farm building still requires a permit10.
  • Effective March 1, 2025, detached accessory buildings need a recorded affidavit and interior plans from the zoning office before the county will issue the permit, so budget the extra step and time8.
  • A building permit expires 12 months after it's issued, with only one extension of up to 180 days, so don't let a slow project run out the clock8.

Sources

  1. St. Clair County Building Regulations, Chapter 7, quoted and re-checked
  2. St. Clair County Building Regulations, Chapter 7, quoted and re-checked
  3. St. Clair County Building Regulations, Chapter 7, quoted and re-checked
  4. Zoning Ordinance, quoted and re-checked
  5. St. Clair County Private Sewage Disposal Code, quoted and re-checked
  6. Health Department - Private Sewage Disposal Code, quoted and re-checked
  7. Water & Private Sewage, quoted and re-checked
  8. St. Clair County Building & Zoning Department – Building Permits (co.st-clair.il.us)
  9. St. Clair County Health Department – Water & Private Sewage (scchealthdept.com)
  10. St. Clair County Zoning Code, Chapter 40, quoted and re-checked
  11. Median property tax bill: Bolthole Index county data
  12. Effective property tax rate: Bolthole Index county data
  13. Chapter 7 - Building Regulations, quoted and re-checked
  14. St. Clair County Building Regulations, Chapter 7, quoted and re-checked
  15. Chapter 7 - Building Regulations, quoted and re-checked
  16. St. Clair County Building & Zoning Department (co.st-clair.il.us)
  17. St. Clair County Building Regulations, Chapter 7, quoted and re-checked
  18. St. Clair County Zoning Code, quoted and re-checked
  19. St. Clair County Zoning Code, quoted and re-checked
  20. St. Clair County Zoning Code, quoted and re-checked
  21. St. Clair County Zoning Code, quoted and re-checked
  22. St. Clair County Private Sewage Disposal Code, quoted and re-checked
  23. 77 Ill. Adm. Code 905.190 Installation Approval (Illinois statewide rule), quoted and re-checked
  24. Share of soils USDA rates "not limited" for a conventional septic drain field (SSURGO). A strict rating: the median county is about 6% and a tenth of counties are 0%, so a low figure means most lots need a site evaluation or an engineered system, not that septic is impossible. Cite it only with that caveat: Bolthole Index county data
  25. co.st-clair.il.us, quoted and re-checked
  26. St. Clair County Zoning Code, Chapter 40, quoted and re-checked
  27. St. Clair County Building Regulations, Chapter 7, quoted and re-checked
  28. 77 Ill. Adm. Code 905.130 Human Waste Disposal (Illinois statewide rule), quoted and re-checked
  29. Health Department - Private Sewage Disposal Code, quoted and re-checked
  30. St. Clair County Zoning Code, Chapter 40, quoted and re-checked
  31. St. Clair County Building Regulations, quoted and re-checked
  32. St. Clair County Zoning Code, Chapter 40, quoted and re-checked
  33. St. Clair County Building Regulations, Chapter 7, quoted and re-checked
  34. St. Clair County Subdivision Code, quoted and re-checked
  35. Straight-line distance from the county center to the nearest city of 100,000+ people: Bolthole Index county data

Written October 9, 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.

Found land here? Start a Property Hunt →

Compared with neighboring counties

Like all 6 of its neighbors, St. Clair County requires a building permit for a home.

RuleSt. Clair CountyMonroe CountyMadison CountyClinton CountyWashington CountyRandolph CountyBond County
Building permitRequiredRequiredRequiredRequiredRequiredRequiredRequired
County zoningYesYesYesYesYesYesYes
Septic permitsCounty Health Dept.County Health Dept.County Planning & Development Dept.County Health Dept.County Health Dept.County Health Dept.County Health Dept.

County locator

St. Clair County in Illinois

41
County map
St. Clair County highlighted among the Illinois counties · colored by Index score

How St. Clair County scores

Seclusion16100% ev.
Self-Sufficiency64100% ev.
Admin Boringness4390% ev.
Durability59100% ev.
Property Autonomy42100% ev.
Carry Cost55100% ev.

Evidence strength: 98%. This reports direct-source completeness and fallback use; it is separate from the score and is not a confidence interval. How it works →

$181kTypical home
2.1%Property tax
$9,310Land / acre
42.5"Annual rain
2.1% of yrsSevere drought
11.8 / yr (+10.3)Mid-century 100°F days
16.6 daysMid-century dry spell
2" (+9.1%)Mid-century 1-day rain
1.88×Wildfire change factor
100%Forward climate coverage
$1,729Home insurance / yr
4% / yrInsurance growth
0.88%Nonrenewal rate
county median (2+ published ZIPs)Insurance basis
347,843People within 30 min
3,841,263People within 2 hr
306,643Radius comparison (15 mi)
381.7People / sq mi
0.9%Federal land
90.4%Land at 15% slope or less
10.1%Soils rated "not limited" for septic (strict USDA rating)
39,796 acWorkable land screen
28.8%Wooded land
44 tonsBiomass / forest ac
56.3°FAvg temp

Scout St. Clair County

Camp here before you commitBook a few nights nearby on Hipcamp →Already own land here?Earn money hosting campers — get $100 when you become a Hipcamp host →

Some links are affiliate or referral links — we may earn a commission, at no cost to you.

Property hunt

Find land. Bring the promising ones back.

Search live inventory elsewhere, then cost and vet each candidate here. No copied listings, account, or paid data feed.

View your full hunt →
ZillowLand & lotsRealtor.comLand listingsLandSearchRural & vacant land

Each button opens a current land search for St. Clair County. Listing sites control their own results and filters.

Analyze a property
Add setup-cost allowances

Use rough quotes or placeholders. Blank fields count as $0.

Working estimate

—land + entered setup costs
Asking $ / acre
—
Setup allowance
—
All-in $ / acre
—

A planning estimate, not a valuation or contractor quote. The USDA benchmark includes farm land and buildings; it is context, not a parcel comp.

Before an offer

Parcel due diligence

0/8 checked

Saved properties and checklist progress stay on this device. Bolthole Index does not receive them.

Cities and towns in St. Clair County

Inside a city or town, that city usually issues building permits and sets zoning; the county’s rules above cover unincorporated land. Septic, wells and floodplain rules usually stay with the county or state everywhere.

Not yet researched: Village of Brooklyn · Canteen Township · Caseyville Township · Village of Caseyville · Centreville Township · Village of East Carondelet · East St. Louis Township · Engelmann Township · Fairview Heights · Fayetteville Township · Village of Fayetteville · Freeburg Township · Lebanon Township · Lenzburg Township · Village of Lenzburg · Marissa Township · Mascoutah Township · Millstadt Township · New Athens Township · Village of New Baden · O'Fallon Township · Prairie Du Long Township · Village of Sauget · Village of Shiloh · Shiloh Valley Township · Smithton Township · Village of Smithton · St. Clair Township · Village of St. Libory · Stites Township · Stookey Township · Sugar Loaf Township · Village of Summerfield · Village of Swansea · Village of Washington Park

Answers from the rulebook for St. Clair County

What the ordinances and state agencies actually say — one answer per question, each quoted from the official source and independently re-checked.

St. Clair County rules

  • Building permitRequired

    Construction, enlargement, alteration, demolition, moving, occupancy changes, and regulated electrical, gas, mechanical, or plumbing work under St. Clair County Building Regulations.

    • A permit must be obtained before covered work begins.
    • Permits are not required for one-story detached accessory structures used as tool or storage sheds, playhouses, and similar uses when floor area does not exceed 120 square feet.
    • Permits are not required for fences no higher than 7 feet, specified oil derricks, retaining walls no higher than 4 feet unless supporting a surcharge or impounding Class I, II, or III-A liquids, and water tanks supported directly on grade when capacity does not exceed 5,000 gallons and height-to-width or diameter ratio does not exceed 2 to 1.
    • Permits are not required for listed minor finish work, certain swimming pools less than 24 inches deep and no greater than 5,000 gallons installed entirely above ground, specified agricultural shade cloth structures, playground equipment, certain window awnings, and nonfixed movable fixtures and partitions no higher than 5 feet 9 inches.
    • Electrical, gas, mechanical, and plumbing exemptions apply only as specifically listed in Section 7-1-28.
    • For emergency equipment replacements and repairs, the permit application must be submitted by the next working business day.
    • Ordinary repairs do not require application or notice, but do not include structural changes, changes to required means of egress, or work affecting public health or general safety.
    • A permit is not required for specified public-service-agency equipment under established ownership and control.
    “7-1-27 Required. Any owner or authorized agent who intends to construct, enlarge, alter, repair, move, demolish, or change the occupancy of a building or structure, or to erect, install, enlarge, alter, repair, remove, convert or replace any electrical, gas, mechanical or plumbing system, the installation of which is regulated by this code, or to cause any such work to be done, shall first make application to the building official and obtain the required permit. (IBC 105.1)”
    2 more reviewed findings on this topic
    • Required — Construction, enlargement, alteration, repair, moving, demolition, or occupancy changes regulated by the county building code.
      “Any owner or authorized agent who intends to construct, enlarge, alter, repair, move, demolish, or change the occupancy of a building or structure, or to erect, install, enlarge, alter, repair, remove, convert or replace any electrical, gas, mechanical or plumbing system, the installation of which is regulated by this code, or to cause any such work to be done, shall first make application to the building official and obtain the required permit.”
    • Required — Construction, enlargement, alteration, repair, moving, demolition, occupancy changes, and regulated electrical, gas, mechanical, or plumbing work.
      “shall first make application [...] and obtain the required permit.”
  • Building code adoptedAdopted (with conditions)

    County Building Regulations governing buildings and structures in the county jurisdiction.

    • The 2012 International Building Code is adopted in part with county additions, insertions, deletions, and changes.
    • Detached one- and two-family dwellings and qualifying townhouses comply with Article II of Chapter 7.
    • Existing buildings undergoing repair, alteration, addition, or change of occupancy may comply with the county Property Maintenance Code.

    adopted code: International Building Code 2012 (adopted in part)

    “"The International Building Code, 2012" [...] is hereby adopted in part”
    One more reviewed finding on this topic
    • Adopted (with conditions) — County Building Regulations for buildings and structures within the county building-code jurisdiction.
      “That a certain document, one (1) copy of which is on file in the office of the Zoning Administrator of St. Clair County, being marked and designated as "The International Building Code, 2012" as published by the International Code Council be and is hereby adopted in part and as contained herein as the “Building Regulations” of St. Clair County, Illinois, for the control of buildings and structures as herein provided; and each and all of the regulations, provisions, penalties, conditions and terms of said International Building Code, 2012, are hereby referred to, adopted and made a part hereof as if fully set out in this Article, with the additions, insertions, deletions and changes, if any, prescribed herein.”
  • InspectionsRequired

    Required inspections for work performed under a county building permit.

    • The building official must make required inspections or may accept reports from approved agencies or individuals.
    • Agricultural structures, public schools, and township structures are exempt from building inspections and fees when used exclusively for the related activity.
    • Inspections include footing, plumbing, electrical, framing, insulation, and final inspections as applicable.
    “shall make all of the required inspections”
    One more reviewed finding on this topic
    • Required — Construction or work for which a county building permit is required.
      “Construction or work for which a permit is required shall be subject to inspection by the building official and such construction or work shall remain accessible and exposed for inspection purposes until approved.”
  • Certificate of occupancyRequired

    Use or occupancy of buildings and changes in occupancy classification.

    • Certificates are not required for work exempt from permits under §7-1-28.
    • The building official may issue a temporary certificate before completion if the occupied portion is safe and a validity period is set.
    “No building or structure shall be used or occupied, and no change in the existing occupancy classification of a building or structure or portion thereof shall be made until the building official has issued a certificate of occupancy therefor as provided herein.”
  • County-wide zoningPresent (with conditions)

    County zoning regulation in the unincorporated areas of St. Clair County.

    • The zoning district boundaries are established by the county zoning map.
    • Municipal zoning may apply within incorporated municipalities.
    • Scott Air Force Base is excluded from the county zoning-district boundary rule quoted in the source.
    “entire County of St. Clair outside the limits of cities”
    One more reviewed finding on this topic
    • Present (with conditions) — County zoning controls in the unincorporated areas of St. Clair County and in municipalities that are not otherwise zoned by their own municipal authority.
      “40-1-3 JURISDICTION. It is hereby declared that the provisions of this code shall apply to all unzone municipalities and to all properties in the unincorporated part of St. Clair County as provided herein, except those properties occupied by Scott Air Force Base.”
  • Local zoningVaries (with conditions)

    County aggregate conclusion covering county zoning in unincorporated areas and unzoned municipalities, alongside separate zoning jurisdictions of zoned incorporated municipalities.

    • The county code expressly applies to unzoned municipalities and unincorporated property, but excludes properties occupied by Scott Air Force Base.
    • The code separately refers to zoned cities, villages, and incorporated towns, so the county ordinance does not provide a single zoning regime for every incorporated place.
    • This is an aggregate countywide conclusion and does not claim that St. Clair County administers each municipal zoning ordinance.
    “Any additions to the unincorporated area of the county, resulting from disconnection by any zoned city, village, or incorporated town or otherwise, or from submerged land which may be reclaimed or additions by any means whatsoever, shall be automatically classified in the “A” Agricultural Industry District until duly changed by an amendment to this code.”
    One more reviewed finding on this topic
    • Varies (with conditions) — Aggregate conclusion for St. Clair County: county zoning applies in unincorporated areas, while incorporated municipalities may administer their own zoning.
      “which have in effect municipal zoning codes”
  • Zoning districtsPublished (with conditions)

    County zoning districts and boundaries.

    • The zoning district map is incorporated by reference into the Zoning Code.
    • Where land is not shown in a district, the most restrictive adjoining district governs, except for land within Scott Air Force Base.
    “The boundaries of the zoning district are established as shown on the St. Clair County Zone District Map. The zoning districts and boundaries are hereby adopted and established as shown on the Zone District Map, which map, together with all notations, references, data, district boundaries and other information thereof, are made a part of the Zoning Code by reference.”
    One more reviewed finding on this topic
    • Published (with conditions) — County zoning districts and their dimensional standards in unincorporated St. Clair County.
      “ARTICLE IV USES PERMITTED BY ZONING DISTRICT”
  • Minimum lot sizeSpecified

    Lots requiring private sewage disposal; this is a Health Department wastewater requirement, not a general county zoning lot-size conclusion.

    • One acre usable space is required for a residential structure requiring private sewage disposal, excluding lakes, ponds, and easements.
    • Within subdivisions served by municipal water, the minimum is one acre usable space.
    • Within subdivisions without available municipal water, the minimum is three acres usable space.
    • The Health Department may require more area, allow a variance, or consider pre-existing platted lots under stated conditions.

    minimum usable lot area with private sewage, ordinary residential: >= 1 acre (excluding lakes, ponds, and easements) · minimum usable lot area with private sewage, subdivision without municipal water: >= 3 acres (excluding lakes, ponds, and easements)

    “Minimum lot size for a residential structure requiring a private sewage disposal system shall be one (1) acre usable space in size excluding lakes, ponds and easements. A greater area may be required for such lots if, in the opinion of the Health Department, there are other factors of drainage, soil conditions, or other conditions which may cause potential health problems.”
    One more reviewed finding on this topic
    • Specified — Lots in county zoning districts in unincorporated St. Clair County.
      “11 NB 1 per 20,000 sq. ft. 20,000 sq. ft.”
  • SetbacksSpecified

    Yard and setback requirements for county zoning districts.

    • Setbacks vary by district and yard type; the zoning table includes front-yard, side-yard, rear-yard, and lot-line requirements, with exceptions in the notes.
    “Note 3: 25’ if abutting “A”, “RR”, “SR”, “MH”, “MR”, or “NB”; otherwise 0’ or a minimum of 12’”
    One more reviewed finding on this topic
    • Specified — Buildings and lots in county zoning districts.
      “Every lot with multiple frontages (such as corner or through lots) shall meet the front setback requirements of the district in which it is located on every side having frontage, unless otherwise provided herein.”
  • Lot coverageSpecified

    District-specific zoning bulk regulations.

    • The zoning-code district table identifies maximum lot coverage as a district bulk standard.
    • Numeric coverage limits vary by district and were not fully extracted here.
    “maximum lot coverage shall be indicated in column “K”; maximum principal building height shall be indicated in column “L”; maximum heights for accessory buildings and uses shall be indicated in column “M”;”
  • Building heightSpecified

    Principal-building height in county zoning districts.

    • The general table states a 35-foot maximum for principal buildings, with governmental structures allowed up to 100 feet; additional district-specific or special-area rules may apply.

    principal building height: <= 35 ft (governmental buildings and structures may be no more than 100 ft)

    “The maximum of height of the principal building, excluding buildings and structures used for governmental purposes, shall be 35 ft. Buildings and structures used for governmental purposes shall have a maximum of no more than 100 ft.”
    One more reviewed finding on this topic
    • Specified — Structures in county zoning districts, including the AO-3 Airport Overlay District.
      “The maximum height of any structure within the Installation Buffer for shall be 35 feet. However, this maximum height limitation shall not be applicable to any governmental use, building, or structure.”
  • Camping on your landLimited

    Private recreational areas or camps in county-zoned areas.

    • Private recreational areas or camps are listed as special uses when not operated for profit.
    • A special-use approval is therefore required where the cited provision applies.
    “Private recreational areas or camps, when not operated for profit.”
  • Manufactured homesLimited

    Manufactured-home occupancy in county zoning districts.

    • The MHP district is intended for permanent one-family-per-manufactured-home occupancy.
    • Manufactured homes are subject to district and Section 40-5-12 requirements.
    • Manufactured housing is prohibited in the AO-3 Installation Buffer.
    • Temporary parking has separate limits and permit requirements.

    temporary parking outside public right-of-way: 72 hours (minimum 25 feet from public-street right-of-way) · temporary parking on zoning lot: 2 weeks (permit required within 72 hours; no more than 3 permits per owner per calendar year absent ZBA approval)

    “The “MHP” Manufactured Home Park District is intended exclusively for INDEPENDENT MANUFACTURED HOME location and permanent one family per manufactured home occupancy plus only such accessory uses and activities as are customary and necessary for direct and immediate use of occupants and for the management, operation, maintenance, and safety of the Manufactured Home Park.”
  • Who permits septicMixed (with conditions)

    Private sewage systems in St. Clair County.

    • IDPH licenses private sewage installers and related businesses.
    • St. Clair County licenses private sewage installers, pumpers, pumper trucks, and aeration service providers.
    • County requirements and the Illinois Department of Public Health code both apply.
    “IDPH licenses the private sewage installers, private sewage pumpers, portable sanitation businesses and portable sanitation technicians. St. Clair County licenses private sewage installers, private sewage pumpers, private sewage pumper trucks and aeration service providers.”
    One more reviewed finding on this topic
  • Septic permitRequired

    Construction, alteration, or extension of individual domestic sewage disposal systems in St. Clair County.

    • Applications must be made to the Health Department.
    • Permits are issued only to a homeowner or St. Clair County licensed private sewage disposal installation contractor.
    • The Health Department refuses a permit where a sanitary sewer is available; availability includes a sewer within or abutting the right-of-way or a practical connection within 300 feet for a single-family residence or 1,000 feet for a commercial establishment, subdivision, or multifamily dwelling.
    • The permit is valid for one year from issuance.
    • Routine cleaning, replacing septic tank covers, and rodding inlets and outlets do not require a construction permit.
    • The initial construction, alteration, or extension permit fee is $300.

    single-family sewer-distance threshold: <= 300 feet (reasonable-distance rule) · commercial, subdivision, or multifamily sewer-distance threshold: <= 1000 feet (reasonable-distance rule) · permit validity: 1 year (from date of issuance) · initial permit fee: 300 USD (construction, alteration, or extension)

    “It shall be unlawful for any person to construct, alter or extend individual domestic sewage disposal systems within St. Clair County unless he/she holds a valid permit issued by the Health Department stating the name of such person for which the specific construction, alteration or extension is proposed.”
    One more reviewed finding on this topic
  • Septic inspectionLimited

    Operational inspection of a private sewage disposal system involved in a property sale or refinancing.

    • An operational inspection may be conducted when an application is submitted to the Health Department.
    • The inspection fee is $300.
    • The owner or occupant must provide reasonable access for compliance inspections.

    operational inspection fee: 300 USD (sale or refinancing application)

    “An operational inspection may be conducted”
  • Off-grid sanitationLimited

    Private sewage disposal as an alternative to sanitary sewer service.

    • Private sewage systems require a Health Department permit.
    • The Health Department must refuse a private sewage permit when a sanitary sewer is available under the county's distance and practicality rules.
    • Approved systems must comply with the county code and incorporated state code.
    “where a sanitary sewage system is available.”
  • Well permitRequired

    Newly installed or renovated private wells in the 18 townships under the St. Clair County Health Department's jurisdiction.

    • All new or renovated wells must be constructed by an Illinois Department of Public Health licensed well driller.
    • The county health office performs on-site construction and final inspection.
    • The permit fee is $200.

    well permit fee: 200 USD

    “All newly installed or renovated wells must be constructed by an Illinois Department of Public Health licensed well driller. All installations must obtain a permit for $ 200.00 from this office.”
  • Mandatory utility hookupConditional

    Utility connections to buildings or systems regulated by the county building code.

    • A connection requires approval or release by the building official.
    • Temporary connections may be authorized.
    • Unauthorized connections may be disconnected in emergencies or when required approval was not obtained.
    “No person shall make connections from a utility, source of energy, fuel or power to any building or system that is regulated by this code for which a permit is required, until released by the building official.”
    One more reviewed finding on this topic
    • Conditional — Connection of utility, energy, fuel, or power service to a building or system regulated by the county building code.
      “No person shall make connections from a utility, source of energy, fuel or power to any building or system that is regulated by this code for which a permit is required, until released by the building official.”
  • Agricultural exemptionAvailable (with conditions)

    Buildings and structures occupied by persons primarily engaged in agriculture and used or intended for agricultural purposes.

    • Agricultural buildings and structures must still conform to building setback lines.
    • Permits for covered agricultural construction are issued free of charge.
    • If part of the tract ceases to be used solely for agriculture, the zoning code applies to that part.
    • Residential dwellings and non-exclusive agricultural buildings in the agricultural district still require a building permit.
    “The provisions of this code shall not be exercised or administered to impose regulations with respect to the erection, maintenance, repair, alterations, remodeling or extensions of buildings or structures occupied by those engaged primarily in the occupation of agriculture, used, or intended to be used for agricultural purposes upon such land, except that buildings or structures for agricultural purposes shall be required to conform to building setback lines.”
  • Subdividing landRegulated (with conditions)

    Subdivision or resubdivision of land in unincorporated St. Clair County.

    • A plat must be approved before recording.
    • Subdivision is generally the division into two or more lots, sites, or parcels where any is less than five acres, or dedication of a road, highway, street, or alley regardless of area.
    • Municipal review applies when the subdivision lies within 1.5 miles of a municipality with subdivision regulations or an official plan.
    • Preliminary and final plat fees are $40 per lot with a $300 minimum and $25 per lot with a $100 minimum, respectively.

    municipal-review proximity: <= 1.5 miles (municipality with subdivision regulations or official plan) · preliminary plat fee: per 40 USD per lot (minimum $300 per plat) · final plat fee: per 25 USD per lot (minimum $100 per plat)

    “No plat of any subdivision shall be entitled to record [...] until it has been approved”
    One more reviewed finding on this topic
    • Regulated (with conditions) — Subdivision or resubdivision of land in unincorporated St. Clair County.
      “It shall be unlawful for any person, or agent, having control of any land within the unincorporated area of the County of St. Clair, Illinois, to subdivide land, except by a plat which is in accordance with the regulations contained herein.”
  • Driveway accessLimited

    Development abutting a designated Major Area Service Highway.

    • A Special Highway Access Permit must be approved in writing by the County Highway Engineer before on-site grading or issuance of a building permit.
    • The provision is limited to designated Major Area Service Highways.
    “The use and/or development of any lot or tract of land that abuts a Major Area Service Highway, or part thereof as hereinafter designated, shall require a Special Highway Access Permit approved by the County Highway Engineer in writing prior to on-site grading or the issuance of a building permit.”
  • Building in a floodplainLimited

    Permitted construction in flood-hazard areas under the county building code.

    • Elevation documentation for the lowest floor must be submitted before final inspection when the project is in a flood-hazard area.
    • Other county floodplain and zoning requirements may also apply.
    “If located in a flood hazard area, documentation of the elevation of the lowest floor as required in Section 1612.5 shall be submitted to the building official prior to the final inspection.”
  • Permit feesPublished (with conditions)

    County building permits and inspections.

    • Residential fees vary by type, square footage, construction cost, and additional inspections.
    • The code states that other fees, including water taps, sewer connections, electrical permits, and occupancy certificates, may also apply.

    single-family residence up to 2500 square feet: 500 USD · single-family residence 2501 square feet or more: 700 USD · additional inspection: 75 USD · manufactured or modular home: 150 USD ($300 if placed over a basement)

    “Single-Family Residential. A building permit and inspections of Single-Family Residence with two thousand five hundred (2,500) square feet and under of living space the fee shall be Five Hundred Dollars ($500.00). Single Family Residence with two thousand five hundred one (2,501) square feet and over of living space the fee is Seven Hundred Dollars ($700.00).”
    One more reviewed finding on this topic
    • Published (with conditions) — County building permits and related regulated systems.
      “On buildings, structures, electrical, gas, mechanical and plumbing systems or alterations requiring a permit, a fee for each permit shall be paid as required, in accordance with the schedule as established by St Clair County Ordinance No 13-1087;11-25-13).”
  • Permit processPartial

    Published county building-permit application and inspection process for unincorporated St. Clair County.

    • The permit applicant must file a written application on a department form identifying the work, location, use and occupancy, valuation, and other required information.
    • The application must include construction documents and other information required by Section 7-1-36.
    • The building official examines applications and issues a permit when the work conforms to applicable code, laws, and ordinances.
    • The application is deemed abandoned after 180 days unless pursued in good faith or a permit is issued; extensions may be granted for additional periods not exceeding 90 days each when requested in writing with justifiable cause.
    • The property must have an assigned address before a building permit is issued.
    • Before applying, an Energy Code Compliance Certificate must be generated for residential or commercial work.
    • Residential applications require one set of plans drawn to scale; commercial or industrial applications require one set of plans and specifications prepared by a licensed Illinois architect, with the seal on all sheets and an architect letter.
    • Plan review fees are $100 commercial and $75 residential, effective January 1, 2020; the information sheet states a 48-hour review period for all permits.
    • The building permit must be posted; inspections require 24 hours advance notice with the permit number, construction address, and owner's name.
    • All required inspections are covered under the building permit; a failed inspection requires a $75 re-inspection fee before the next inspection.
    • This claim is partial because the reviewed official county materials establish a building-permit process but do not establish a complete process for every county zoning, private-sewage, or well application.

    commercial plan review fee: 100 USD (effective January 1, 2020) · residential plan review fee: 75 USD (effective January 1, 2020) · application abandonment period: 180 days (unless pursued in good faith or a permit has been issued) · inspection notice: >= 24 hours (before needing an inspection) · failed inspection re-inspection fee: 75 USD (must be paid before the next inspection)

    “Property must have an assigned address from the 9-1-1 Coordinating office prior to a building permit being issued. [...] 2. Building permit shall be posted. 3. Must call 24 hours prior to needing any inspection. Please have your permit number; construction address and owners name prior to calling. 4. All required inspections are covered under building permit. 5. Upon failing an inspection a $75.00 re-inspection fee must be paid prior to next inspection.”
    2 more reviewed findings on this topic
    • Published (with conditions) — County building-permit application and inspection process.
      “Any owner or authorized agent who intends to construct, enlarge, alter, repair, move, demolish, or change the occupancy of a building or structure, or to erect, install, enlarge, alter, repair, remove, convert or replace any electrical, gas, mechanical or plumbing system, the installation of which is regulated by this code, or to cause any such work to be done, shall first make application to the building official and obtain the required permit.”
    • Published (with conditions) — County building-permit application and review process.
      “The building official shall examine or cause to be examined applications for permits and amendments thereto within a reasonable time after filing. If the application or the construction documents do not conform to the requirements of pertinent laws, the building official shall reject such application in writing, stating the reasons therefor. If the building official is satisfied that the proposed work conforms to the requirements of this code and laws and ordinances applicable thereto, the building official shall issue a permit therefor as soon as practicable.”

Illinois rules that apply here

  • Owner-builder exemptionConditional

    Owner occupants or lessee occupants of single-family residences, and owners of single-family residences under construction for their own occupancy, performing plumbing planning, installation, alteration, or repair in Illinois.

    • The exemption is limited to plumbing work on the specified single-family residence; the cited statute does not establish a general owner-builder exemption for all construction trades or a statewide exemption from building permits.
    • The plumbing must comply with the minimum standards in the Illinois State Plumbing Code.
    • The plumbing is subject to inspection by the Illinois Department of Public Health or by the local governmental unit if it retains a licensed plumber as inspector.
    • The owner, owner occupant, or lessee occupant may not employ anyone other than a plumber licensed under the Illinois Plumbing License Law to assist.
    • An occupant must have taken possession of and be living in the premises as their bona fide sole and exclusive residence, or, for a residence under construction, expect to take possession and live there as that residence, with current intent to live there for at least 6 months after completion of the plumbing work or, for a residence under construction, at least 6 months after completion of construction.
    • Failure to possess and live in the premises as a sole and exclusive residence for 6 months or more creates a rebuttable presumption that the required intent was lacking.

    minimum occupancy period: >= 6 months (After completion of plumbing work; for a residence under construction, after completion of construction.)

    “Nothing herein contained shall prohibit the owner occupant or lessee occupant of a single family residence, or the owner of a single family residence under construction for his or her occupancy, from planning, installing, altering or repairing the plumbing system of such residence”
    2 more reviewed findings on this topic
    • Conditional — Privately funded construction in Illinois, including projects performed by an owner-builder, as to state-issued building permits, state plan review, state building-code inspections, and state occupancy permits.
      “No. If any of these are required, they would be addressed by the unit of local government.”
    • Conditional — Statewide treatment of local plumbing permits and inspections for qualifying owner occupants performing plumbing work on a single-family residence.
      “Nothing contained in this Act shall prohibit any city, town, village, township or county from providing for a Plumbing Inspector or from requiring permits for the installation and repair of plumbing and collecting a fee therefor, but a city, town, village, township, or county that requires a permit for installation and repair of plumbing may not issue that permit without verification that the applicant has a valid plumbing license or that the applicant is the owner occupant of a single family residence that is the subject of the permit.”
  • Short-term rentalsLimited

    Short-term rentals in Illinois where at least one room is rented for fewer than 30 consecutive days and accommodations are reserved in advance, when the hosting platform meets the statutory definition of a re-renter.

    • Beginning July 1, 2025, qualifying hosting platforms are subject to Hotel Operators’ Occupation Tax.
    • The source establishes tax and registration obligations, not statewide land-use permission; local zoning and licensing may separately apply.

    rental period: < 30 consecutive days

    “Beginning July 1, 2025, hosting platforms for short-term rentals that meet the definition of “re-renter” are subject to Hotel Operators’ Occupation Tax.”
  • Campground & park staysAllowed (with conditions)

    Overnight camping in Illinois campgrounds subject to the Campground Licensing and Recreational Area Act.

    • IDPH annually inspects and licenses campgrounds in Illinois.
    • The state campground definition includes camping and temporary parking of recreational vehicles.
    • Campgrounds within home rule units of government are exempt from the state campground licensing requirement.
    • Recreational areas without overnight camping, such as highway rest stops and picnicking areas, are subject to the rules but are not licensed or routinely inspected.

    minimum persons for statutory campground threshold: >= 10 persons · minimum camping duration for statutory campground threshold: >= 6 camping days per calendar year

    ““Camping Day” means any 24 hour period or portion thereof during which the participants remain overnight at the site.”
  • county building authorityLimited

    County building-construction and building-code regulation, including residential structures, in counties meeting the statutory population and metropolitan-area conditions.

    • The county must have a population not in excess of 1,000,000.
    • The county must be located in the area served by the Northeastern Illinois Metropolitan Area Planning Commission.
    • Rules are subject to rules or regulations adopted by the State Fire Marshal under the cited gasoline and volatile-oils statute.
    • The county must exempt municipalities located wholly or partly within the county when the municipal building code is equal to the county regulation and local authorities are enforcing that municipal code.
    • The rules apply throughout the county, but municipalities may establish higher standards.
    • The rules do not apply to construction or alteration of buildings or structures used or to be used for agricultural purposes on a tract zoned and used for agricultural purposes.
    • The county board must follow the publication and posting requirements in 55 ILCS 5/5-1063.
    • Beginning on the effective date of the amendatory Act of the 92nd General Assembly, a county adopting a new building code or amending an existing building code must provide the building-code identification to the Capital Development Board under Section 10.18 at least 30 days before adoption.
    • Violations are petty offenses, and enforcement is by an officer designated by county-board resolution.
    • The provision expressly authorizes county building-construction and building-code rules, but the opened text does not expressly use the phrase residential building permit requirement.

    population threshold: <= 1000000 persons (The county must be located in the area served by the Northeastern Illinois Metropolitan Area Planning Commission.) · pre-adoption identification period: >= 30 days (Applies to a new building code or amendment under the stated amendatory-Act provision.)

    “The county board in any county with a population not in excess of 1,000,000 located in the area served by the Northeastern Illinois Metropolitan Area Planning Commission may prescribe by resolution or ordinance reasonable rules and regulations (a) governing the construction and alteration of all buildings and structures and parts and appurtenances thereof and governing the maintenance thereof in a condition reasonably safe from the hazards of fire, explosion, collapse, contagion and the spread of infectious disease”
    One more reviewed finding on this topic
    • General — Illinois counties adopting and enforcing building codes and issuing building permits for residential construction in unincorporated areas, subject to the statewide baseline framework.
      “A municipality or county is not required to adopt building codes. If they do NOT adopt a building code then they are considered a non-building code jurisdiction and section 10.09-1 of the Capital Development Board Act (20 ILCS 3105) applies. If they do adopt a building code(s) then it must comply with section 10.18 of the Capital Development Board Act (20 ILCS 3105).”

Still unanswered

We looked and could not find an official answer yet. Silence is not permission — ask the county directly.

  • Minimum dwelling size — Minimum dwelling size in county zoning districts.
  • Living in an RV — Long-term or residential recreational-vehicle occupancy on private land.
  • Tiny homes — Tiny-home occupancy on private land.
  • Accessory dwellings — Accessory dwelling units in county zoning districts.

Each answer was extracted from an official source and independently re-checked against that source by a second reviewer. That is an evidence check, not legal advice. Rules change; confirm with the authority before you buy or build.

Living off-grid in St. Clair County, Illinois

Is St. Clair County a good place to live off-grid or homestead?

St. Clair County scores 41/100 on the Bolthole Index, a marginal county profile. Its strengths: workable self-sufficiency basics (42.5″/yr rainfall) and mixed durability signals. Watch-outs: about 347,843 people within a 30-minute drive.

Do you need a building permit in St. Clair County, Illinois?

St. Clair County generally requires a residential building permit, and it enforces county zoning. Onsite septic is permitted by St. Clair County Health Department. Owner-builders may act as their own contractor to build their home. These answers are quoted from official sources and independently re-checked. Rules change and cities within the county differ — always confirm with the county before you buy or build.

How much does land cost in St. Clair County, Illinois?

Land in St. Clair County runs about $9,310 per acre, based on the latest county data.

What is the water situation in St. Clair County?

St. Clair County gets about 42.5" of rain a year, with severe drought in roughly 2.1% of years.

How remote is St. Clair County?

A representative private-land location has about 347,843 people within a 30-minute drive and 3,841,263 within two hours. The road-network catchments count population across county lines and clusters of smaller cities; straight-line radius values remain available as a comparison.

How St. Clair compares in Illinois

Compare side-by-side →See all 102 Illinois counties ranked →