Bolthole Index

Washington County, Illinois

Zoning, building permits and septic rules in Pilot Knob Township, Illinois

Pilot Knob Township is a township in Washington County, Illinois. Septic permits inside Pilot Knob Township come from Washington County. 9 rules below are quoted from official sources and independently re-checked, most recently on October 30, 2026. Rules for unincorporated land are on the Washington County page.

Answers from the rulebook for Pilot Knob Township

Rules another office applies inside Pilot Knob Township

Pilot Knob Township does not set these itself; the county, a health district or the state does, and they apply to every address inside its limits.

  • Building permitRequired

    All construction on land inside Pilot Knob township that is under Washington County's zoning authority, including agricultural buildings.

    • The county statement applies to construction in Washington County; municipal limits are not covered by this county statement.
    • The certificate of zoning compliance must be obtained before construction begins (see the certificate claim).
    “all construction in washington county requires a building permit including agricultural buildings!”
  • Local zoningPresent (with conditions)

    Unincorporated land inside Pilot Knob township, Washington County, IL, under the county's zoning ordinance. This is a county-administered ordinance, not an ordinance adopted by Pilot Knob township.

    • The county's zoning ordinance is titled the Washington County Revised Zoning Ordinance on the county zoning page; the county's own zoning page lists it but the ordinance text was not opened in this research.
    • Incorporated municipalities inside the county are not covered by this county claim.
    • No official Pilot Knob township zoning ordinance was located.
    “before beginning any construction, a certificate of zoning compliance must be obtained from the zoning administrator.”
  • Zoning districtsPartial

    Zoning districts that apply to unincorporated land inside Pilot Knob township

    • The flyer names the three most common districts (AG, R-1, R-2); the full district list is in the revised zoning ordinance, which was not opened.
    • Other districts in the ordinance may apply to specific parcels.
    “the three most common districts and their minimum lot sizes are: ag-40 acres, r-1 (rural residential) 2 acres, and r-2 (urban residential) 1 acre.”
  • Minimum lot sizeDistrict specific (with conditions)

    Parcels in the county's AG (agricultural) zoning district inside Pilot Knob township's unincorporated land

    • Parcels in an AG district divided below 40 acres generally need a rezoning, usually to R-1 or R-2, before construction is allowed.
    • Exception: an existing homesite that has existed since 1980 may be separated and built on without rezoning.
    • Exception: a buyer who is agriculturally exempt (actively engaged in agriculture and owns at least 40 acres) is another exception to the rezoning process.
    • Lots under 40 acres in an AG district created before 1980 zoning are grandfathered per the flyer.
    • The minimum is stated in the county zoning office's flyer; the ordinance text itself was not opened.

    minimum lot size (AG district): >= 40 acres (Existing 1980 homesite exception; agricultural-exemption buyer exception; pre-1980 grandfathered lots)

    “the three most common districts and their minimum lot sizes are: ag-40 acres, r-1 (rural residential) 2 acres, and r-2 (urban residential) 1 acre.”
    One more reviewed finding on this topic
    • District specific (with conditions) — Parcels in the county's R-1 (Rural Residential) zoning district inside Pilot Knob township's unincorporated land
      “the three most common districts and their minimum lot sizes are: ag-40 acres, r-1 (rural residential) 2 acres, and r-2 (urban residential) 1 acre.”
  • Who permits septicCounty (with conditions)

    Private sewage disposal systems on land inside Pilot Knob township, served by the Washington County Health Department (which covers the whole county, including this township)

    • The county health department's Environmental Health function regulates private sewage disposal systems per its job flyer.
    • Health department office: 177 S. Washington St., Nashville, IL 62263; phone (618) 327-3644.
    “inspection and regulation of food service facilities, private sewage disposal systems, and private water supplies”
  • Agricultural exemptionConditional

    Parcels in agricultural use inside Pilot Knob township's unincorporated area, for a buyer who is building on a divided parcel

    • The exemption applies if the buyer is actively engaged in agriculture and owns at least 40 acres.
    • Whether construction is allowed without rezoning under this exemption is per the county zoning office's flyer; the ordinance was not read.
    “another exception to this process is if the buyer, the one building on the property is agriculturally exempt (actively engaged in agriculture and owns at least 40 acres).”
  • Permit feesPublished (with conditions)

    Building permits for construction inside Pilot Knob township's unincorporated area

    • The zoning office issues building permits for construction; the fee quoted applies if the structure is over 150 square feet.
    • A separate certificate-of-zoning-compliance application lists a $100 fee on its face is not confirmed in the text opened, so only the flyer figure is recorded.

    building permit fee: 100 USD (Charged if structure is over 150 square feet)

    “zoning office issues building permits for any construction. a fee of $100 is charged if over 150 square feet.”
  • Permit processPartial

    Obtaining a zoning certificate and building permit for construction inside Pilot Knob township's unincorporated area

    • A certificate of zoning compliance is issued within a few days if the construction meets zoning requirements; if the administrator finds noncompliance, the applicant may request a zoning board of appeals interpretation, a variance, a zoning amendment, or a special use permit.
    • The application needs a legal description or E-911 address or parcel number and a site plan with measurements from property lines.
    • Applications may be submitted online per the county zoning page; the office is in the old jail building at 125 W. St. Louis St., Nashville.
    “if the proposed construction meets the zoning requirements, a permit will be issued within a few days.”

Still unanswered

We looked and could not find an official answer yet. Silence is not permission; ask Pilot Knob Township or Washington County directly.

  • Owner-builder exemption — Whether an owner-builder may build a home on land inside Pilot Knob township without a contractor
  • Building code adopted — Which building code, if any, governs new construction inside Pilot Knob township
  • Inspections — Building inspections for new construction on land inside Pilot Knob township
  • Certificate of occupancy — A certificate of occupancy for a finished building on land inside Pilot Knob township
  • Minimum dwelling size — Minimum dwelling size for a new home on land inside Pilot Knob township
16 more unanswered
  • Setbacks
  • Lot coverage
  • Building height
  • Living in an RV
  • Camping on your land
  • Tiny homes
  • Manufactured homes
  • Accessory dwellings
  • Septic permit
  • Septic inspection
  • Off-grid sanitation
  • Well permit
  • Mandatory utility hookup
  • Driveway access
  • Building in a floodplain
  • Short-term rentals

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.

Unanswered questions are usually a sign that Pilot Knob Township publishes no rule on the point, not that none exists. Washington County’s page lists the county offices to call.

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