Zoning, building permits and septic rules in Deer Park Township, Illinois

Rules another office applies inside Deer Park Township

Deer Park 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 code adoptedAdopted (with conditions)

  Residential structures requiring building permits in the unincorporated portion of Deer Park Township.

  • The County page says this applies to residential structures that require building permits.
  • The County notice states the update was effective January 1, 2025.

  residential code: International Residential Code 2024 (as amended by the LaSalle County Board) · electrical code: National Electrical Code 2023 (as amended by the LaSalle County Board)

  “Residential Structures that require Building Permits are subject to the International Residential Codes - for one and two family dwellings, 2024 and 2023 National Electric Code as amended by the LaSalle County Board.”

• InspectionsRequired

  Structures receiving County building permits in the unincorporated portion of Deer Park Township.

  • Agricultural buildings are exempt from local County building-code inspections but remain subject to building codes and Illinois Department of Public Health plumbing inspections.

  “Building Code inspections will apply to all structures which receive Building Permits.”

• Certificate of occupancyRequired

  Occupancy and use of a structure in the unincorporated portion of Deer Park Township.

  • Issued after a final inspection is completed and certified passing.
  • For structures with wells or septic, Health Department response/approval certification is also required.

  “Occupancy and use of a structure (which includes but is not limited to moving furniture and personal items into the structure) is forbidden without an Occupancy Permit.”

• Zoning districtsPublished (with conditions)

  Unincorporated land in Deer Park Township subject to the LaSalle County Zoning Ordinance; parcel district must be confirmed from the County map.

  • The County zoning webpage cautions that its electronic ordinance and maps may not be the current official record; the print version plus subsequent County Board amendments control.

  districts: A-1, AC, R-1, R-2, R-3, B-1, B-2, I-1 (unincorporated area)

  “In order to carry out the purpose and intent of this Ordinance, the unincorporated area of the County is hereby divided into the following districts:”

• Minimum lot sizeSpecified

  Single-family detached dwellings in the A-1 Agriculture District in the unincorporated portion of Deer Park Township, if mapped A-1.

  • Except as otherwise provided in the ordinance.

  minimum lot area: >= 35 acres (A-1 single-family detached dwellings) · minimum lot width: >= 150 feet (A-1 single-family detached dwellings)

  “Single Family Detached Dwellings: The zoning lot shall be not less than thirty-five (35) acres.”

• SetbacksSpecified

  Single-family detached dwellings in the A-1 Agriculture District in the unincorporated portion of Deer Park Township, if mapped A-1.

  • Front setback depends on roadway classification.
  • In all cases front setback must be at least 30 feet from the road right-of-way or roadway-easement edge.
  • Side and rear measurements are from the property line.

  township-road front setback: 70 feet (measured from road centerline) · county-road front setback: 85 feet (measured from road centerline) · state-road front setback: 100 feet (measured from road centerline) · side and rear setback: 10 feet

  “In all cases the setback shall be a minimum of 30 feet from the edge of the road right-of-way or edge of the roadway easement.”

• Manufactured homesAllowed (with conditions)

  A-1 Agriculture District in the unincorporated portion of Deer Park Township, if the parcel is mapped A-1.

  • Must be a mobile or manufactured doublewide home.
  • Must have a permanent foundation, be at least 1,000 square feet, and be less than 10 years old.

  minimum floor area: >= 1000 square feet (doublewide manufactured home with permanent foundation) · maximum age: < 10 years

  “Mobile or Manufactured (doublewide) Home with a permanent foundation, 1000 square feet or greater, and less than 10 years old.”

• Who permits septicCounty (with conditions)

  Private sewage disposal serving land in Deer Park Township where County Health Department permitting applies.

  • Construction permit issuance requires a completed application, fee, and onsite survey by Health Department personnel.

  “A permit for construction will not be issued until a completed application and fee have been submitted to the LaSalle County Health Department and an onsite survey performed by department personnel.”

• Septic permitRequired

  Construction of a private sewage disposal system in Deer Park Township where County Health Department permitting applies.

  • Completed application, fee, and onsite survey are prerequisites.
  • The application states a $230 application fee; if denied, the fee is returned.

  application fee: 230 USD (returned if permit is denied)

  “there is a two hundred thirty ($230.00) dollar application fee for a private sewage disposal system permit. If a permit is denied, the fee shall be returned to the applicant.”

• Septic inspectionRequired

  Private sewage disposal system construction in Deer Park Township where County Health Department permitting applies.

  • The Health Department must be notified before backfilling.
  • Inspection produces a statement whether the system meets current Illinois Department of Public Health standards.

  “The Health Department must be notified for a final inspection sewage disposal system construction before backfilling.”

• Well permitRequired

  Construction of a new well inside Deer Park Township.

  • Applies before construction of a new well.

  “Prior to the construction of a new well, a permit from the Health Department is required to ensure the protection of groundwater.”

• Agricultural exemptionConditional

  Bona fide agricultural buildings, accessory structures, and structures in the unincorporated portion of Deer Park Township.

  • A building permit and zoning certificate remain required.
  • The exemption is from County building-code inspections and building-code fees, not from setbacks or other applicable local, state, or federal rules.
  • Agricultural operation must produce gross income of $5,000 or more and proof from the preceding calendar year is required.

  minimum agricultural gross income: >= 5000 USD (proof of preceding-calendar-year income required)

  “Buildings, accessory structures and structures that are used for Bona Fide Agricultural Uses require a building permit and zoning certificate. If these structures are declared Bona Fide Agriculture Structures and will be used for agricultural purposes they are exempt from County building code inspections and building code fees.”

• Subdividing landRegulated (with conditions)

  Property subdivision in the unincorporated portion of Deer Park Township.

  • The County directs applicants to verify compliance with the County Subdivision Ordinance, County Zoning Ordinance, and Illinois Plat Act before subdividing.

  “Please contact our department prior to subdividing property in order to verify that the split will comply with the LaSalle County Subdivision, LaSalle County Zoning Ordinance, and the Illinois Plat Act.”

• Building in a floodplainRequired

  Construction in floodplain areas of the unincorporated portion of Deer Park Township.

  • Construction and modifications may also require permits from other local entities and state and federal agencies.

  “The Department enforces the LaSalle County Floodplain Ordinance in the unincorporated areas of the County. All construction occurring in the floodplain requires a permit from the LaSalle County Land Use Department.”

• Permit processPublished (with conditions)

  County building-permit applicants in the unincorporated portion of Deer Park Township.

  • Two copies of construction documents, a site diagram, approved well and septic permits where applicable, and truss certificates where used are listed as attachments.
  • Applications missing appropriate information and attachments will not be accepted.

  “Two copies of construction documents shall be provided, which clearly show it will conform to the provisions of the applicable adopted codes (1 set will be returned) (11x17 max preferred) (Plan review can be expedited with additional submittal of PDF plans).”

Still unanswered

We looked and could not find an official answer yet. Silence is not permission; ask Deer Park Township or LaSalle County directly.

• Owner-builder exemption — Owner-built residential construction in the unincorporated portion of Deer Park Township.
• Local zoning — Land inside Deer Park Township.
• Minimum dwelling size — Single-family dwellings in the unincorporated portion of Deer Park Township.
• Lot coverage — A-1 Agriculture District in the unincorporated portion of Deer Park Township.
• Building height — A-1 Agriculture District in the unincorporated portion of Deer Park Township.

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.