Zoning, building permits and septic rules in Mendota Township, Illinois

Rules another office applies inside Mendota Township

Mendota 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

  New buildings, accessory structures, decks and structural alterations in unincorporated land inside Mendota township (not the City of Mendota)

  • Building permit applies when a structure is 200 square feet or larger, or has a side of 20 feet or greater.
  • Construction that begins before a permit is issued is subject to a penalty of double the permit fee.
  • Agricultural buildings are handled under a separate exemption (see agricultural_exemption claim).

  minimum structure size triggering building permit: >= 200 square feet (or a side of 20 feet or greater)

  “building permits are required for: any…. building, accessory structure, structure, deck, rebuilding, structurally altering, adding to, relocation, or significant change of use, of structure in unincorporated lasalle county if…. the structure is one of the following: 1. 200 s.f. or larger or; 2. has a side of 20 feet or greater”

• Building code adoptedAdopted (with conditions)

  Residential structures requiring a county building permit in unincorporated land inside Mendota township

  • Non-agricultural commercial, industrial, institutional and multi-family buildings are subject to the International Building Code, 2024, and related 2024 ICC codes, per the brochure.
  • The brochure lists the codes as enforced by the county; the residential code year is not stated in the excerpt.

  “residential structures that require building permits are subject to the international residential codes”

• InspectionsRequired

  Structures that receive a county building permit in unincorporated land inside Mendota township

  • Inspections are scheduled through the county inspection line; the brochure says to allow 48 hours for scheduling.
  • Agricultural structures declared bona fide agriculture are exempt from county building code inspections.

  “*building code inspections will apply to all structures which receive building permits.”

• Certificate of occupancyRequired

  Occupancy and use of a structure permitted under a county building permit in unincorporated land inside Mendota township

  • The county issues an occupancy permit after a final passing inspection.
  • The owner must certify that the LaSalle County Health Department has approved the well and septic before the occupancy permit is issued; health approval can take at least 48 hours.

  “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)

  Zoning districts for unincorporated land inside Mendota township; the township's district map is adopted within the county ordinance

  • Districts are A-1, AC, RR, R-2, R-3, B-1, B-2 and I-1; the zoning map of each township is adopted by reference.
  • Parcel-level district assignment requires the county zoning map (not opened).

  “the location and boundaries of the districts established by this ordinance are as shown on the zoning district map of each township of the county”

• Minimum lot sizeSpecified

  Single-family detached dwelling on a parcel zoned RR rural residence district by the LaSalle County zoning map, in unincorporated land inside Mendota township (not the City of Mendota)

  • Applies only where the county zoning map places the parcel in the RR rural residence district.
  • Minimum lot width of 150 feet applies to all permitted or special uses in this district.

  minimum zoning lot area, single-family detached dwelling: >= 1 acre (planned unit developments have no minimum lot area) · minimum lot width, all permitted or special uses: >= 150 feet (except as otherwise required herein)

  “single family detached dwellings: the zoning lot shall not be less than one (1) acre in size.”

  One more reviewed finding on this topic

  • Specified — Single-family detached dwelling on a parcel zoned A-1 agriculture district by the LaSalle County zoning map, in unincorporated land inside Mendota township (not the City of Mendota)

    “single family detached dwellings: the zoning lot shall be not less than thirty-five (35) acres.”

• SetbacksSpecified

  Principal buildings on A-1 agriculture district parcels in unincorporated land inside Mendota township (not the City of Mendota)

  • Front yard is measured from the centerline of the roadway; the setback is never less than 30 feet from the edge of the road right-of-way or roadway easement.
  • Front setback is 85 feet from a county road centerline and 100 feet from a state road centerline.
  • Other bulk rules in the county zoning ordinance and the county setback ordinance also apply.

  front yard setback from township road centerline: 70 feet (85 feet for county roads, 100 feet for state roads; minimum 30 feet from road right-of-way edge) · side yard setback: 10 feet · rear yard setback: 10 feet

  “properties facing township roadways have a seventy (70) foot setback from the centerline of the roadway.”

• Building heightSpecified

  Dwelling units on A-1 agriculture district parcels in unincorporated land inside Mendota township

  • On zoning lots of one acre or greater, there is no height limit for non-dwelling buildings.

  maximum building height, dwelling units: <= 36 feet (on zoning lots of one acre or greater, no height limit applies to non-dwelling buildings)

  “on zoning lots with less than one (1) acre of land area, and on all buildings used as dwelling units the building height shall not exceed thirty-six (36) feet in height.”

• Living in an RVLimited

  Living or sleeping in a recreational vehicle on private land in unincorporated land inside Mendota township

  • Not allowed for living or sleeping in a subdivision, an unincorporated platted town, or on a parcel with an existing residence, unless otherwise permitted by the ordinance.
  • Limit applies to living or sleeping use; the county zoning ordinance applies in unincorporated areas only.

  maximum living or sleeping use per calendar year: <= 180 days (not allowed on parcels with an existing residence or in subdivisions or platted towns)

  “a recreational vehicle, as defined in chapter 3, may be used for living or sleeping purposes for a period not exceeding 180 days in a calendar year.”

• Who permits septicCounty (with conditions)

  Private sewage disposal systems on parcels in unincorporated land inside Mendota township

  • Governed by the Private Sewage Disposal Licensing Act and Code, administered through the LaSalle County Health Department (815-433-3366).
  • Not a township-level rule; the township does not administer septic per the cited pages.

  “private sewage disposal licensing act and code water well construction code for more information contact the lasalle county health department at 815-433-3366”

• Septic permitRequired

  New residential construction needing a county building permit in unincorporated land inside Mendota township

  • An approved septic permit from the LaSalle County Health Department must be attached to the county building permit application.
  • Construction is still governed by the Private Sewage Disposal Licensing Act and Code; health permit terms were not extracted.

  “copy of approved septic permit from lasalle county health department”

• Septic inspectionRequired

  Completed residences with a septic system in unincorporated land inside Mendota township, before occupancy

  • The health department must issue its approval, certified by the owner to the building inspector, before the county occupancy permit is issued.
  • Health approval certification can take at least 48 hours.

  “it is the responsibility of the owner to contact, request, and certify to the building inspectors that the lasalle county health department has issued their approval.”

• Well permitRequired

  New residential construction with a water well in unincorporated land inside Mendota township

  • An approved well permit from the LaSalle County Health Department must be attached to the county building permit application.
  • Well construction is governed by the water well construction code cited by the brochure (text not extracted).

  “copy of approved well permit from lasalle county health department”

• Agricultural exemptionConditional

  Bona fide agricultural buildings in unincorporated land inside Mendota township

  • Requires an owner's sworn affidavit and proof of gross agricultural income in the prior calendar year.
  • Agricultural structures are not exempt from setbacks, and remain subject to Illinois Department of Public Health plumbing inspections.
  • A $25.00 agriculture exempt compliance fee applies, which is not a building permit fee.

  gross agricultural income required: >= 5000 USD (proof required from prior calendar year)

  “so long as said bona fide agricultural use produces gross income of $5,000.00 or more to the operator.”

• Subdividing landRegulated (with conditions)

  Creation of new lots or parcels in unincorporated land inside Mendota township

  • Lots created by subdivision or deed division must follow the LaSalle County subdivision control ordinance.
  • Subdivision compliance is a prerequisite listed before a county building permit is issued.

  “such lots, created by subdivision or deed division, shall be required to make land/cash donations in accordance with the lasalle county subdivision control ordinance.”

• Driveway accessRequired

  Driveway and road access for a building permit in unincorporated land inside Mendota township

  • The LaSalle County highway access ordinance must be met before a building permit issues.
  • The county highway department administers it at 815-434-0743; the access ordinance text was not opened.

  “lasalle county highway access ordinance for more information contact the lasalle county highway department at 815-434-0743”

• Permit feesPublished (with conditions)

  County building permit fees for nonagricultural one- and two-family dwellings and accessory structures in unincorporated land inside Mendota township

  • Fees are set by a schedule in Article 6 of the LaSalle County building permit ordinance (schedule not opened); the price is set by the building inspector after plan review.
  • Fees are nonrefundable and paid when the permit is issued.

  agriculture exempt compliance fee: 25 USD (not a building permit fee; applies to bona fide agriculture structures)

  “fees are based on square footage of structure and the number of inspections required. the fee schedule can be found in the lasalle county building permit ordinance”

• Permit processPublished (with conditions)

  County building permit applications for structures in unincorporated land inside Mendota township

  • Apply at least 30 days before anticipated construction.
  • Attachments: building permit application, two sets of construction documents, site diagram, approved well and septic permits from the health department, and stamped truss certificates if trusses are used.
  • Inspections are scheduled at 847-510-4104; the Land Use Department is at 815-434-8666.

  “apply for a permit at least 30 days in advance of anticipated building”

Still unanswered

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

• Owner-builder exemption — Owner-builder construction of a home in unincorporated land inside Mendota township
• Local zoning — Land inside Mendota township (LaSalle County, IL) outside the City of Mendota
• Minimum dwelling size — Single-family dwellings in unincorporated land inside Mendota township
• Lot coverage — Lots in unincorporated land inside Mendota township
• Camping on your land — Temporary camping on private land inside Mendota township outside the City of Mendota

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.