Bolthole Index

Washington County, Illinois

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

56Index Score / 100
#60 of 102 in Illinois

Unincorporated Washington County, Illinois requires building permits, including for agricultural buildings, and county zoning approval before construction12. Qualifying farm structures pay no filing fee, but still need a building permit3. Inside incorporated municipalities, building-permit and zoning authority must be checked separately; septic systems remain regulated by Illinois Department of Public Health (IDPH), with local health agencies potentially reviewing plans45.

At a glance

Building permit
Required for all construction, including agricultural buildings1
Zoning
County zoning covers unincorporated land; municipal zoning must be checked separately64
Permit fees
Published; qualifying agricultural buildings are fee-exempt but still need a permit73
Septic
Regulated by Illinois IDPH; local health agencies may review plans5
Private well
Permit required before construction, modification or sealing8
RV or tiny-home living
County occupancy rules were not confirmed; ask the Zoning Office9
Owner-builder exemption
State plumbing allowance is limited; a county building-permit exemption is unconfirmed101

Who to call

Zoning

Washington County Zoning Office

Building permits and county zoning administration

(618) 327-4800 (ext. 345)

125 W. St. Louis St. Nashville, IL 62263

Health department

Washington County Health Department

Environmental health and local private sewage system permitting

(618) 327-3644

healthdepartment@washingtonco.illinois.gov

177 S. Washington St. Nashville, IL 62263

Roads & driveways

Washington County Highway Department

County roads and rights-of-way; ask whether a county-road entrance needs approval

(618) 327-4800 (ext. 350)

1243 W. Adams St. Nashville, IL 62263

Contact details are copied from each office’s official page and were checked against it on October 12, 2026.

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Do you need a building permit in Washington County, Illinois?

Washington County requires a building permit for construction under county jurisdiction, including agricultural buildings1. Farm structures qualifying under Section 4-13 of the county zoning code have no filing fee; that exemption does not waive the building permit3. The published schedule lists no fee for structures under 150 square feet and a $100 fee for structures at or above 150 square feet7. Obtain a Certificate of Zoning Compliance before construction begins2. Illinois has had statewide building codes since 2025; locally adopted residential codes must regulate structural design at least as stringently as the International Residential Code (IRC), while jurisdictions without an adopted code follow the state’s residential framework11. Ask the county or municipal code official which code governs the project11.

Who handles building permits in Washington County, Illinois?

The Washington County Zoning Office is the contact for county building permits and zoning administration1213. The office is at 125 W. St. Louis St. in Nashville, can be reached at (618) 327-4800 extension 345, and is open weekdays from 8am to 4pm14. Inside a city or village, confirm whether that municipality issues the parcel’s building permit4. County applications require applicant/owner authorization, a legal description or E-911 address or parcel number, and a site plan with measurements from property lines and other buildings215. A noncompliant proposal may need an interpretation, variance, zoning amendment, or special-use permit2. We could not confirm a building-inspection schedule, county-adopted code edition, or certificate-of-occupancy process; ask the office issuing the building permit216.

Does Washington County, Illinois have zoning?

Washington County zoning governs unincorporated land6. Published classifications include Agricultural, Commercial, Industrial, Interchange, and R-1, but the available provisions do not establish a complete district schedule; ask the Zoning Office for the parcel’s district and applicable use and dimensional rules1718. Centralia, a city reaching into Washington County but mainly in Marion County, administers its own zoning19. Septic regulation remains with IDPH and any participating local health agency5. Commercial solar facilities have setbacks of 150 feet from nonparticipating dwellings and occupied community buildings, and 50 feet from nonparticipating property lines and public road rights-of-way20. Those commercial solar setbacks do not establish house setbacks; we could not confirm ordinary residential setbacks, minimum lot or dwelling size, or general height limits, so ask the Zoning Office before choosing a house site2018.

How do septic and well permits work in Washington County?

Illinois IDPH regulates private sewage systems serving Washington County; local health agencies may review plans under local ordinances or as IDPH agents5. Illinois requires septic plan approval from IDPH or the applicable local authority before construction, plus at least 48 hours’ notice before installation or modification begins21. Contact the Washington County Health Department first to identify the reviewing authority and septic application for the address225. Only 3.2% of county soils are rated without severe limits for a conventional drain field, making a site evaluation an early purchase priority23. Eligible surface-discharging systems also face Illinois EPA authorization, inspection, monitoring, and reporting requirements2425. Private-well construction, modification, or sealing needs a permit from IDPH or an approved local health department before work begins26.

Can you live in an RV or tiny home in Washington County?

We could not confirm a Washington County rule allowing or prohibiting long-term RV occupancy, temporary camping on private land, or tiny-home occupancy; ask the Washington County Zoning Office about the proposed use9. For unincorporated land, ask the Washington County Zoning Office about the district, duration, and utility arrangement; inside a city or village, ask the municipal zoning office4. Illinois campground licensing does not answer whether one household may occupy an RV on its own parcel27. A tiny home involving construction under county jurisdiction still needs a building permit, and its proposed residential use must fit the applicable zoning district2818. Septic plan review remains an IDPH or participating local-health-agency question regardless of which office handles building permits or zoning5.

Building a home in Washington County: the steps, in order

  1. Determine whether the parcel is unincorporated or inside a city or village, then ask the zoning authority for the district, allowed use, setbacks, and any variance or special-use need294.
  1. Contact the Health Department to identify who reviews the septic plan, and complete that review before fixing the house location225.
  1. If the property needs a private well, obtain the required well permit before work begins8.
  1. For a county-administered parcel, submit the Certificate of Zoning Compliance application with authorization, parcel identification, and a measured site plan15.
  1. Obtain the building permit from County Zoning or the applicable city or village284.
  1. Ask the issuing office which inspections and final approvals apply, because we could not confirm that schedule2.

What should you check before buying land in Washington County?

Start with jurisdiction and buildability. Confirm whether the parcel is unincorporated or inside a municipality, identify the applicable zoning district, and get written answers on the dwelling, setbacks, access, and parcel division294. Test the proposed sewage area early: only 3.2% of Washington County soils are rated without severe limits for conventional drain fields23. The terrain is broadly workable, with 95.2% of land at a slope of 15% or less, but that does not replace a site survey or drainage review30. Check whether floodway authorization is needed; regulated rural floodways generally include streams draining at least 10 square miles31. The effective property-tax rate is 1.8%, with a median annual bill of $2,7663233.

Watch-outs

  • Washington County’s agricultural filing-fee waiver and zero fee for structures under 150 square feet do not establish building-permit exemptions371.
  • Washington County-specific rules for RV occupancy, tiny homes, minimum dwelling size, and general residential setbacks remain unconfirmed; ask the Zoning Office about the parcel and proposed use9.
  • A county-road driveway rule was not confirmed; ask the Highway Department before altering a county right-of-way, while state-road work requires an IDOT permit3435.
  • Illinois allows qualifying residents to perform plumbing on a single-family home subject to code and inspection conditions; that allowance does not waive county building permits or all local plumbing permits1036.

Sources

  1. Zoning | Washington County, Illinois, quoted and re-checked
  2. Washington County Form #1 — Application for Certificate of Zoning Compliance, quoted and re-checked
  3. Washington County Illinois Zoning 2023, quoted and re-checked
  4. Washington County Illinois – Revised Zoning Ordinance, quoted and re-checked
  5. Private Sewage Disposal, quoted and re-checked
  6. Zoning | Washington County, Illinois, quoted and re-checked
  7. Washington County Illinois Zoning 2023, quoted and re-checked
  8. Private Water & Closed Loop Wells, quoted and re-checked
  9. Zoning | Washington County, Illinois (2026 county census)
  10. HB5913 Enrolled — Illinois Plumbing License Law amendment (Illinois statewide rule), quoted and re-checked
  11. Building Codes and Regulations | Illinois Capital Development Board, quoted and re-checked
  12. Zoning | Washington County, Illinois, quoted and re-checked
  13. Zoning | Washington County, Illinois, quoted and re-checked
  14. Washington County Zoning Office (washingtonco.illinois.gov)
  15. Washington County Application for Certificate of Zoning Compliance, quoted and re-checked
  16. Building Codes and Regulations, quoted and re-checked
  17. Washington County, Illinois Revised Zoning Ordinance, quoted and re-checked
  18. Washington County Illinois – Revised Zoning Ordinance, quoted and re-checked
  19. Centralia: Centralia Municipal Code, Sec. 2-488 — Powers and duties (Washington County), quoted and re-checked
  20. Washington County Illinois – Revised Zoning Ordinance, quoted and re-checked
  21. 77 Ill. Adm. Code 905.190 Installation Approval (Illinois statewide rule), quoted and re-checked
  22. Washington County Health Department (washingtonco.illinois.gov)
  23. 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
  24. Illinois Surface Discharge Permit (ILG62), quoted and re-checked
  25. Illinois Surface Discharge Permit (ILG62), quoted and re-checked
  26. 77 Ill. Admin. Code 920.130, Water Well Permit Requirements (Illinois statewide rule), quoted and re-checked
  27. Youth Camps and Campgrounds (Illinois statewide rule), quoted and re-checked
  28. Zoning | Washington County, Illinois, quoted and re-checked
  29. Zoning | Washington County, Illinois, quoted and re-checked
  30. Share of land at 15% slope or less: Bolthole Index county data
  31. Permit Program (Illinois statewide rule), quoted and re-checked
  32. Effective property tax rate: Bolthole Index county data
  33. Median property tax bill: Bolthole Index county data
  34. Washington County Highway Department (washingtonco.illinois.gov)
  35. Highway Permits (Illinois statewide rule), quoted and re-checked
  36. 225 ILCS 320/18 — Local regulation; Department standards (Illinois statewide rule), quoted and re-checked

Written October 12, 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.

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Compared with neighboring counties

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

RuleWashington CountyPerry CountyClinton CountyJefferson CountySt. Clair CountyRandolph CountyFranklin County
Building permitRequiredRequiredRequiredRequiredRequiredRequiredRequired
County zoningYesYesYesYesYesYesNot published
Septic permitsCounty Health Dept.County Health Dept.County Health Dept.County Health Dept.County Health Dept.County Health Dept.Franklin-Williamson Bicounty Health Dept.

County locator

Washington County in Illinois

56
County map
Washington County highlighted among the Illinois counties · colored by Index score

How Washington County scores

Seclusion41100% ev.
Self-Sufficiency61100% ev.
Admin Boringness4390% ev.
Durability51100% ev.
Property Autonomy42100% ev.
Carry Cost60100% 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 →

$168kTypical home
1.8%Property tax
$8,068Land / acre
44.2"Annual rain
2% of yrsSevere drought
11.3 / yr (+10.1)Mid-century 100°F days
16.2 daysMid-century dry spell
2.04" (+8.7%)Mid-century 1-day rain
1.89×Wildfire change factor
100%Forward climate coverage
$1,729Home insurance / yr
3.2% / yrInsurance growth
0.76%Nonrenewal rate
county median (2+ published ZIPs)Insurance basis
26,711People within 30 min
3,696,510People within 2 hr
27,032Radius comparison (15 mi)
24.1People / sq mi
0%Federal land
95.2%Land at 15% slope or less
3.2%Soils rated "not limited" for septic (strict USDA rating)
11,435 acWorkable land screen
15.9%Wooded land
62.3 tonsBiomass / forest ac
55.7°FAvg temp

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Cities and towns in Washington 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 Addieville · Ashley · Ashley Township · Beaucoup Township · Bolo Township · Covington Township · Du Bois Township · Village of Du Bois · Hoyleton Township · Village of Hoyleton · Irvington Township · Village of Irvington · Johannisburg Township · Lively Grove Township · Nashville Township · Village of New Minden · Oakdale Township · Village of Oakdale · Okawville Township · Village of Okawville · Pilot Knob Township · Plum Hill Township · Village of Radom · Richview Township · Village of Richview · Venedy Township · Village of Venedy · Wamac

Answers from the rulebook for Washington County

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

Washington County rules

  • Building permitRequired

    Construction subject to Washington County jurisdiction, including agricultural buildings.

    • The county page states that all construction in Washington County requires a building permit, including agricultural buildings.
    • Municipal permitting may apply within incorporated cities and villages.
    “ALL CONSTRUCTION IN WASHINGTON COUNTY REQUIRES A BUILDING PERMIT INCLUDING AGRICULTURAL BUILDINGS!”
    2 more reviewed findings on this topic
    • Required — Construction in Washington County, including agricultural buildings.
      “ALL CONSTRUCTION IN WASHINGTON COUNTY REQUIRES A BUILDING PERMIT INCLUDING AGRICULTURAL BUILDINGS!”
    • Required — Construction in Washington County administered through County Zoning.
      “ALL CONSTRUCTION IN WASHINGTON COUNTY REQUIRES A BUILDING PERMIT INCLUDING AGRICULTURAL BUILDINGS!”
  • County-wide zoningPresent (with conditions)

    County zoning administration and zoning compliance requirements in Washington County.

    • The county zoning page identifies a County Zoning Administrator and County Zoning Board of Appeals.
    • The ordinance contains district-specific and use-specific controls.
    “ALL CONSTRUCTION IN WASHINGTON COUNTY REQUIRES A BUILDING PERMIT INCLUDING AGRICULTURAL BUILDINGS!”
    2 more reviewed findings on this topic
    • Present (with conditions) — Washington County zoning regulations in the county's unincorporated areas.
      “Krystal Althoff Zoning Administrator [...] Washington County Illinois – Revised Zoning Ordinance”
    • Present (with conditions) — Washington County's Revised Zoning Ordinance in the county's unincorporated areas.
      “After the effective date of this revised ordinance no signs shall be erected in the unincorporated areas of the County except in conformity with the requirements of this section.”
  • Local zoningVaries (with conditions)

    Aggregate local zoning across Washington County's unincorporated areas and incorporated municipalities.

    • The county ordinance provision cited here applies to unincorporated areas only.
    • Incorporated municipalities are not established by these sources as being administered by Washington County's zoning office; municipal zoning coverage must be determined separately.
    • The countywide value varies is an aggregate conclusion and does not claim that Washington County administers every local ordinance.
    “Must apply for a building permit from either City/Village or County Zoning. If agriculture exempt – no fee.”
  • Zoning districtsPublished (with conditions)

    County zoning districts and district-based controls under the Revised Zoning Ordinance.

    • The permit application requires the zoning district classification and asks the applicant to identify the zoning district.
    • Specific controls may vary by district and use.
    “7-13.3 SIGNS IN THE COMMERCIAL “C” AND INDUSTRIAL “I” DISTRICTS”
    2 more reviewed findings on this topic
    • Published — Published Washington County zoning-district classifications applicable to the county's unincorporated areas.
      “in the “C” District and “I” Districts [...] In the “A” district and all Interchange districts [...] within one mile of an R-1 District”
    • Partial — Zoning district classifications published in the Washington County Revised Zoning Ordinance and used in county zoning applications.
      “In the “A” district and all Interchange districts, there may be, as a special use, ground signs, or Billboard signs, for off-premises advertising of not more than 1,600 square feet per face or a total of 3,200 square feet for all faces; and further provided that no sign may be placed within one mile of an R-1 District”
  • SetbacksSpecified

    Commercial Solar Energy Facilities in areas governed by Washington County's zoning ordinance.

    • The ordinance governs the siting of Commercial Solar Energy Facilities and Substations that generate electricity to be sold to wholesale or retail markets.
    • Setback distances are measured from the nearest edge of any facility component.
    • Setback requirements for nonparticipating properties may be waived by written consent of each affected nonparticipating property owner.
    • A waiver does not require a County variance; the waiver runs with the land and must be recorded with the County Recorder of Deeds.
    • Other applicable state and federal laws and regulations are not preempted.

    occupied community buildings and dwellings on nonparticipating properties setback: 150 feet (to the nearest point on the outside wall of the structure) · nonparticipating residences setback: 150 feet (to the nearest point on the outside wall of the structure) · boundary lines of participating property setback: None · boundary lines of nonparticipating property setback: 50 feet (to the nearest point on the property line of the nonparticipating property) · public road rights-of-way setback: 50 feet (to the nearest edge of the public road right-of-way)

    “The Commercial Solar Energy Facility shall be sited as follows, with setback distances measured from the nearest edge of any component of the facility:”
  • Agricultural exemptionAvailable (with conditions)

    County filing fees for buildings or structures used for agricultural purposes as defined by Section 4-13 of the Washington County Zoning Code.

    • The exemption is limited to buildings or structures used for agricultural purposes as defined by Section 4-13.
    • The ordinance fee schedule states that the filing fee is zero dollars; the county zoning page separately states that all construction requires a building permit.

    filing fee: 0 USD (Agricultural purposes as defined by Section 4-13 of the Washington County Zoning Code)

    “Buildings or structures to be used for agricultural purposes as defined by Section 4-13 of the Washington County Zoning Code (Ag exempt) No Fee ($0.00)”
    2 more reviewed findings on this topic
    • Conditional — Buildings or structures used for agricultural purposes as defined by Section 4-13 of the Washington County Zoning Code.
      “Buildings or structures to be used for agricultural purposes as defined by Section 4-13 of the Washington County Zoning Code (Ag exempt) No Fee ($0.00)”
    • Conditional — County filing fees for buildings or structures used for agricultural purposes as defined by Section 4-13 of the Washington County Zoning Code.
      “Buildings or structures to be used for agricultural purposes as defined by Section 4-13 of the Washington County Zoning Code (Ag exempt) No Fee ($0.00)”
  • Permit feesPublished (with conditions)

    County zoning-compliance and building filing fees listed in the Revised Zoning Ordinance.

    • Zoning Certificate of Compliance: $100.00.
    • Special Use Permit: $100.00 plus $50.00 publication cost.
    • Zoning Map Amendment, Appeal, and Variance: $100.00 plus $50.00 publication cost.
    • Agricultural structures qualifying under Section 4-13: $0.00.
    • Structures under 150 square feet: $0.00; structures 150 square feet and above: $100.00.
    • Wind and solar farm fee: $7,250.00 per MW in Attachment B; Attachment A separately lists Wind & Solar Farms at $5,000.00 per MW up to $250,000.00, so the applicable schedule should be confirmed for the particular filing.

    Zoning Certificate of Compliance: 100 USD · Special Use Permit: 100 USD (plus $50.00 publication cost) · structures 150 square feet and above: 100 USD

    “Zoning Certificate of Compliance $100.00 $0.00”
    2 more reviewed findings on this topic
  • Permit processPublished (with conditions)

    County zoning-compliance permit process before construction.

    • A Certificate of Zoning Compliance must be obtained before construction begins.
    • The application must be made by the applicant or duly authorized agent with owner permission if the applicant is not the owner.
    • A legal description, E-911 address or parcel number, and site plan with measurements must be included.
    • If the proposal does not comply, the applicant may request a Zoning Board of Appeals interpretation, variance, zoning amendment, or special-use permit.
    • All requested information must be provided before permits are issued.
    • If zoning requirements are met, the permit will be issued within a few days.
    “Before beginning any construction, a Certificate of Zoning Compliance must be obtained from the Zoning Administrator.”
    2 more reviewed findings on this topic

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.”
  • Building code adoptedPartial

    Building-code requirements statewide in Illinois, including residential and commercial construction subject to the Capital Development Board Act baseline requirements.

    • Effective 2025-01-01, Illinois requires statewide baseline building-code requirements.
    • Local governments may adopt building codes, but they are not required to adopt codes; jurisdictions that do not adopt a code are treated as non-building-code jurisdictions and must follow the applicable state-law baseline requirements.
    • For jurisdictions with adopted codes, local codes must regulate structural design at least as stringently as the applicable IRC, IBC, or IEBC baseline.
    • Commercial buildings in non-building-code jurisdictions and state-funded buildings are subject to the state-listed codes and qualified-inspection requirements.
    • Residential requirements differ depending on whether the jurisdiction has adopted a compliant building code and whether the home purchaser and builder agree to an alternative code.

    statewide baseline effective date: 2025-01-01 · local code structural minimum for residential buildings: IRC minimum structural requirements · local code structural minimum for commercial new buildings: IBC minimum structural requirements · local code structural minimum for existing commercial buildings: IEBC minimum structural requirements

    “The State of Illinois recently passed legislation (Public Act 103-0510) changing the Capital Development Board Act to require statewide building codes effective 1/1/2025. [...] Commercial buildings in jurisdictions that have not adopted a building code AND state funded buildings. [...] Starting 1/1/25 local codes must regulate the structural design in a manner that is at least as stringent as the IBC© for new buildings or IEBC© for existing buildings. [...] Residential buildings in jurisdictions that have not adopted a building code where agreed to by the home purchaser and home builder. [...] Residential buildings in jurisdictions that have adopted a building code. [...] Starting 1/1/25 local codes must regulate the structural design in a manner that is at least as stringent as the IRC©.”
    3 more reviewed findings on this topic
    • Adopted (with conditions) — Building-code requirements applicable statewide in Illinois, including Washington County, subject to the distinction between jurisdictions that have and have not adopted local building codes.
      “The State of Illinois recently passed legislation (Public Act 103-0510) changing the Capital Development Board Act to require statewide building codes effective 1/1/2025.”
    • Adopted (with conditions) — Statewide Illinois building-code baseline applicable to residential and commercial construction in Washington County, subject to the jurisdiction's local-code status and the statutory distinctions for adopted and non-building-code jurisdictions.
      “The State of Illinois recently passed legislation (Public Act 103-0510) changing the Capital Development Board Act to require statewide building codes effective 1/1/2025.”
    • Adopted — Statewide baseline building-code requirements for residential construction in Illinois, including jurisdictions with and without locally adopted building codes.
      “Please be advised that the State of Illinois recently passed legislation (Public Act 103-0510) changing the Capital Development Board Act to require statewide baseline building codes effective 1/1/2025. Locally adopted building codes must comply with the requirements of the Act.”
  • InspectionsLimited

    Privately funded construction statewide in Illinois, as to inspections performed by the State rather than by a local authority having jurisdiction.

    • The Illinois Capital Development Board does not perform building-code inspections for privately funded construction.
    • If inspections are required, they are addressed by the applicable unit of local government.
    • A local municipality or county may be a non-building-code jurisdiction, in which case applicable state baseline requirements and inspection-certification provisions may apply.
    “No. If any of these are required, they would be addressed by the unit of local government.”
    One more reviewed finding on this topic
    • Not required — Building-code-compliance inspections performed by the State of Illinois for privately funded construction.
      “No. If any of these are required, they would be addressed by the unit of local government.”
  • Certificate of occupancyLimited

    Occupancy permits or certificates for privately funded construction in Illinois.

    • The State does not issue occupancy permits for privately funded construction.
    • If an occupancy permit is required, it is addressed by the applicable unit of local government.
    “No. If any of these are required, they would be addressed by the unit of local government.”
    One more reviewed finding on this topic
    • Not required — Issuance of occupancy permits or certificates by the State of Illinois for privately funded construction.
      “No. If any of these are required, they would be addressed by the unit of local government.”
  • Building heightDistrict specific (with conditions)

    County zoning districts outside municipalities with municipal zoning ordinances.

    • The applicable county zoning ordinance determines the actual height limit by district or use.
    • No single statewide height measurement was identified.
    “including height of buildings and structures”
  • Manufactured homesAllowed (with conditions)

    Occupancy of manufactured homes as dwellings, including occupancy in manufactured home communities regulated by IDPH.

    • Manufactured home communities with 5 or more sites must be licensed by IDPH, except communities located in home rule units.
    • IDPH annually inspects licensed communities for renewal, including water, sewage disposal, electrical systems, lighting, roads, spacing of homes, and garbage disposal.
    • Manufactured homes moved since January 1, 1980 must be secured using equipment meeting IDPH standards.
    • Effective December 31, 2001, manufactured homes must be installed by an Illinois licensed manufactured home installer or the homeowner and installed according to manufacturer instructions; if unavailable, the IDPH Manufactured Home Installation Code applies.
    • Local zoning, building, floodplain, and utility requirements may also apply.

    manufactured home community license threshold: >= 5 sites (Communities located in home rule units are excepted from this IDPH licensing statement.) · moved-home tiedown requirement effective date: >= 1980-01-01 · installation requirement effective date: >= 2001-12-31

    “designed and situated so as to permit its occupancy as a dwelling place for one or more persons”
  • Who permits septicState (with conditions)

    Private sewage disposal systems serving property in Washington County, subject to Illinois jurisdiction.

    • Local health agencies may review construction plans under local ordinance or as agents of IDPH.
    • Surface-discharging systems may also require Illinois EPA authorization.

    surface discharge threshold: <= 1500 gallons per day (treated effluent discharged to the ground surface)

    “The Illinois Department of Public Health (IDPH) regulates the installation of all private sewage disposal systems that have no surface discharge (such as septic tanks and seepage fields) as well as those that discharge treated effluent up to 1,500 gallons per day to the ground surface (such as sand filters and aerobic treatment systems).”
    One more reviewed finding on this topic
    • Mixed — Installation and plan approval for private sewage disposal systems statewide in Illinois.
      “There are about 90 local health agencies in Illinois that also review sewage disposal system construction plans”
  • Septic permitRequired

    Construction of a new private sewage disposal system statewide, including systems where a septic tank is replaced, a major component is added or removed, or the absorption field changes by at least 25 percent.

    • Plan approval must be obtained from IDPH or the applicable local authority before construction begins.
    • Persons constructing, installing, repairing, or modifying the system must notify the Department or local authority at least 48 hours before work begins.
    • The rule requires submission of plans, site and system information, bedroom count or design volume, soil or percolation information, owner information, and applicant signature.

    notice before commencement: >= 48 hours · absorption-field change threshold: >= 25 percent (The rule treats increasing the field by 25% or more, or removing and replacing 25% or more, as a new system.)

    “Plan approval shall be obtained from the Department or local authority prior to beginning any construction of a new private sewage disposal system.”
    One more reviewed finding on this topic
    • Limited — New and replacement surface-discharging private sewage systems in Washington County.
      “Dischargers who are eligible for coverage under the final general permit will be permitted to discharge pollutants from new and replacement surface discharging private sewage disposal systems to waters of the United States in accordance with the terms and conditions of the general permit.”
  • Septic inspectionLimited

    New and replacement surface-discharging private sewage disposal systems covered by Illinois EPA general NPDES Permit ILG62.

    • Coverage under the general permit is limited to eligible dischargers.
    • Systems not eligible for general-permit coverage may require an individual NPDES permit.
    • Periodic inspection, monitoring, and reporting are required under the permit.
    “The permit sets discharge limits and requires periodic inspection, monitoring and reporting.”
    One more reviewed finding on this topic
    • Limited — Surface-discharging private sewage systems covered by Illinois EPA Permit ILG62.
      “The permit sets discharge limits and requires periodic inspection, monitoring and reporting.”
  • Off-grid sanitationAllowed (with conditions)

    Off-grid disposal of human wastes through privies, portable toilets, recirculation toilets, incinerator toilets, and compost toilets statewide in Illinois.

    • Other domestic wastes must be disposed of in a conventional private sewage disposal system.
    • Compost toilets may also be used for other organic domestic wastes.
    • Privies have construction, capacity, venting, maintenance, and abandonment requirements.
    • A privy pit must have a minimum capacity of 50 cubic feet per seat.
    • A privy must be pumped when filled to within 18 inches of the bottom of the riser.
    • Vault privies are required where groundwater or limestone formations are within 4 feet of the bottom of the pit.
    • Recirculating toilets must meet NSF International/ANSI Standard 41 and residuals must go to an approved public or private sewage disposal system.
    • Incinerator and compost toilets have separate maintenance and disposal requirements; compost toilets must meet NSF International/ANSI Standard 41.

    privy pit minimum capacity: >= 50 cubic feet per seat · privy pumping trigger: <= 18 inches from bottom of riser (Pump when filled to within this distance.) · vault-privy groundwater or limestone separation: < 4 feet from bottom of pit (Watertight, non-metal vaults are required where the condition applies.)

    “Privies, portable toilets, recirculation toilets, incinerator toilets and compost toilets are approved for private sewage disposal of human wastes.”
  • Well permitRequired

    Construction of a new water well, modification of an existing water well, or sealing of an abandoned water well in Illinois.

    • A permit must be obtained from the Illinois Department of Public Health or an approved local health department before work begins.
    • The application must use Department or approved local health department forms and include a plan and drawing of the proposed construction.
    • The plan must include the lot size, slope, property lines, distances to septic tanks, abandoned wells, property lines, seepage fields, sewers, and other contamination sources; driller license number and name; estimated daily pumping capacity if greater than 100,000 gallons per day; well location; owner name and address; well type; estimated depth; well-use type; and proposed aquifer.
    • The permit is void if construction has not commenced within one year after issuance.
    • The permit fee for constructing, deepening, modifying, or sealing a water well may not exceed $100.
    • The Department will deny a permit request when available information indicates groundwater contamination exceeds Class I groundwater standards, subject to the treatment approval provision in subsection (f)(2).
    • The permittee must notify the Department, approved local health department, or approved unit of local government by telephone or in writing at least two days before work begins.

    maximum water well permit fee: <= 100 USD · permit commencement deadline: 1 year after issuance (Permit is void if construction has not commenced within that period.) · pre-work notification: >= 2 days (Notification may be by telephone or in writing.)

    “A permit to construct a new water well, modify an existing water well or seal an abandoned water well shall be obtained from the Department or approved local health department prior to start of work.”
    One more reviewed finding on this topic
    • Required — Construction, modification, or sealing of private water wells in Washington County.
      “To ensure the safety of these water supplies, the IDPH and local health departments review water well installation plans, issue permits for new well construction, and inspect wells.”
  • Driveway accessRequired

    Work within the right-of-way of an Interstate, U.S. state route, Illinois state route, or state-maintained roadway, including access-driveway requests to State highways.

    • A permit must be obtained before work begins.
    • Requirements may vary by IDOT district; the applicant must contact the district office for specific requirements.
    • IDOT's access-driveway handbook guides what is allowable for highway access requests.
    “Per 605 ILCS 5/4 209, IDOT requires a permit when working within the right-of-way of an Interstate, U.S. state route, Illinois state route, or state maintained roadway. A permit must be obtained prior to the start of any work and a copy of the approved permit must be at the worksite at all times.”
  • Building in a floodplainRequired

    Construction activities in regulated Illinois floodways and, where a floodway has not been delineated, generally work anywhere in the floodplain.

    • For downstate streams, IDNR Division permitting applies to floodways of streams draining at least one square mile in urban areas or ten square miles in rural areas.
    • In northeastern Illinois, Part 3708 applies to identified floodways in Cook County excluding Chicago, DuPage, Kane, Lake, McHenry, and Will Counties.
    • Some minor activities are automatically authorized by statewide or regional permits if their terms and conditions are met.
    • For State-owned property, Part 3710 requires a permit for all development activity in FEMA-mapped floodplains.

    urban stream drainage area threshold: >= 1 square mile (regulated floodways under Part 3700) · rural stream drainage area threshold: >= 10 square miles (regulated floodways under Part 3700)

    “All construction activities in the floodways of streams (the channel and the adjacent portion of the floodplain that is needed to safely convey and store flood waters) in urban areas where the stream drainage area is one square mile or more or in rural areas where the stream drainage area is ten square miles or more must be permitted by the Division prior to construction.”
  • 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 floor area in Washington County, including ordinary residential development in unincorporated areas.
  • Minimum lot size — Minimum lot size requirements in Washington County.
  • Lot coverage — Lot-coverage requirements in Washington County.
  • Living in an RV — Long-term RV occupancy on private land in Washington County.
  • Camping on your land — Temporary camping on private land in Washington County.
4 more unanswered
  • Tiny homes
  • Accessory dwellings
  • Mandatory utility hookup
  • Subdividing land

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 Washington County, Illinois

Is Washington County a good place to live off-grid or homestead?

Washington County scores 56/100 on the Bolthole Index, a solid county profile. Its strengths: workable self-sufficiency basics (44.2″/yr rainfall) and higher long-term carry cost. Watch-outs: about 26,711 people within a 30-minute drive.

Do you need a building permit in Washington County, Illinois?

Washington County generally requires a residential building permit, and it enforces county zoning. Onsite septic is permitted by Washington County Health Department, Environmental Health (agent of Illinois DPH). 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 Washington County, Illinois?

Land in Washington County runs about $8,068 per acre, based on the latest county data.

What is the water situation in Washington County?

Washington County gets about 44.2" of rain a year, with severe drought in roughly 2% of years.

How remote is Washington County?

A representative private-land location has about 26,711 people within a 30-minute drive and 3,696,510 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 Washington compares in Illinois

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