Bolthole Index

LaSalle County, Illinois

Building permits, zoning and septic rules in LaSalle, Illinois

LaSalle, Illinois handles building permits through the city Building Inspector; new houses, garages, sheds, fences, decks and patios require building permits.1 LaSalle zoning prohibits RV habitation on residential or commercial premises.2 For private wastewater systems where public sewer is unavailable, LaSalle requires a city permit, while the LaSalle County Health Department administers private sewage installation and repair approvals.34

At a glance

Building permits
City building permits required for new construction and structural alterations1
Zoning
City district rules; R-1 lot and yard dimensions apply to single-family residential land56
RV living
Human habitation prohibited on residential and commercial premises2
Manufactured homes
Mobile homes as defined by the city code prohibited in every zoning district7
Private wastewater
City permit where public sewer is unavailable; coordinate county health approval34
Private wells
Illinois requires a permit before new construction, modification or sealing8

Who to call

Building permits

City of LaSalle Building Department

City building applications, construction guidance and zoning-map access

815-223-3755, ext. 5020

745 Second Street La Salle, Illinois 61301

Building permits

City of LaSalle Building Department — Building Questions

City building-permit requirements and construction inspections

(815) 223-3755 ext. 5020

Septic permits

LaSalle County Health Department

Contact for county private-sewage approvals and questions about the local well-permit authority

815-433-3366

717 E Etna Road Ottawa , IL 61350

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

Off-grid gear

Going off-grid in LaSalle 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 LaSalle, Illinois?

LaSalle requires building permits for new construction, including a house, garage, shed, fence, deck or patio, and when a building’s structure is altered.1 The city also lists new driveways and driveway expansions among work requiring a permit.1 For a LaSalle building-permit application, submit scaled plot plans in duplicate showing the lot, existing and proposed buildings, intended uses and household units; lot dimensions must come from an actual survey, and the lot must be staked before construction.9 LaSalle building-permit fees follow the city fee schedule, and permitted work must be completed within 6 months unless the Building Inspector grants an extension for good cause.10

Who issues building permits and schedules inspections in LaSalle?

The LaSalle Building Inspector’s office is on the second floor of City Hall, in the northeast corner; contact the Building Department at 815-223-3755, ext. 5020.11 The city Building Department provides guidance and oversight for remodeling and new construction.11 LaSalle’s construction-inspection guidance calls for a final inspection upon completion and before occupancy; allow 72 hours from an inspection request to the inspection.1 Ask the Building Inspector to identify the inspections needed for your specific plans before scheduling trades or covering work.1 LaSalle allows homeowners to perform residence repairs in certain situations, but those repairs still need inspection and compliance with building codes.1

Does LaSalle have zoning, and what are the lot sizes and setbacks?

LaSalle’s R-1 Single-family Residence District requires at least 7,500 square feet of lot area per family and a minimum lot width of 60 feet, subject to corner-lot and other table footnotes.5 R-1 front and rear yards must be at least 25 feet deep; either side yard must be at least 7 feet wide, with 14 feet of aggregate side yards.6 LaSalle’s AG-1 Agricultural District also specifies 7,500 square feet per family and 60 feet of lot width, with at least 75 feet of width for corner lots.12 These are district-specific dimensions: ask the Building Inspector to confirm the parcel’s district and applicable exceptions before placing a home on a survey.512

How do septic permits work inside LaSalle?

Where public sanitary or combined sewer is unavailable, LaSalle requires a written private-wastewater construction permit signed by the city’s authorized agent, with plans and specifications and a $25 permit-and-inspection fee paid when filing.3 LaSalle County Health Department’s private-sewage program also covers installations and repairs; the county application requires a fee and an onsite survey before issuance and states a $230 application fee, returned if denied.413 Ask the city Building Inspector and county Health Department to coordinate the required approvals rather than treating the city fee as the entire septic cost.313 For the city’s final private-wastewater inspection, notify the authorized agent before underground portions are covered; the code calls for inspection within 48 hours after notice.14

Can you live in an RV or tiny home in LaSalle?

LaSalle prohibits using a recreational vehicle or motorized home for human habitation while parked or stored on residential or commercial premises, even though the code separately allows limited RV parking and storage.2 That prohibition makes an RV unsuitable as temporary housing on those premises while you build.2 LaSalle also prohibits mobile homes, as defined in its code, in every district within the city’s zoning limits.7 We could not confirm a specific LaSalle tiny-home, accessory-dwelling or minimum dwelling-floor-area rule; ask the Building Inspector about the proposed dwelling’s classification, district and construction requirements before buying a unit.11

Building a home in LaSalle: what should you do first?

  1. Ask the LaSalle Building Inspector to confirm the parcel’s zoning district and review the proposed home against the applicable lot and yard dimensions.56
  2. Resolve wastewater approvals with the city and LaSalle County Health Department if public sewer is unavailable.34
  3. Prepare the surveyed, scaled plot plans, submit the city building application and arrange staking before construction.9
  4. Obtain a LaSalle floodplain development permit before development in a floodplain; the city Building Inspector must obtain other required permits or permit-not-required letters before issuing it.15
  5. Arrange construction inspections and the final inspection before occupancy with the city Building Department.1

Illinois requires a permit before constructing, modifying or sealing a private well; ask LaSalle County Health Department which approved authority handles the proposed address.8 For land outside LaSalle city limits, use the LaSalle County guide for the county’s unincorporated-area building and zoning rules.16

Watch-outs

  • LaSalle RV parking permission does not authorize RV habitation on residential or commercial premises.2
  • LaSalle floodplain rules can reach land outside the mapped floodplain when below base-flood elevation and hydraulically connected to a flood source.15
  • LaSalle subdivision lots may not be sold until the city approves the plat and the plat is recorded.17

Sources

  1. City of LaSalle Building Department — Building Questions (lasalle-il.gov)
  2. § 153.064 Parking/Storage of Vehicles in Residential and Commercial Districts (LaSalle), quoted and re-checked
  3. § 51.03 Private Wastewater Disposal (LaSalle), quoted and re-checked
  4. Sewage Disposal, quoted and re-checked
  5. § 153.045 Table of Height and Area Requirements Adopted (LaSalle), quoted and re-checked
  6. § 153.045 Table of Height and Area Requirements Adopted (LaSalle), quoted and re-checked
  7. § 153.002 Definitions (LaSalle), quoted and re-checked
  8. 77 Ill. Admin. Code 920.130, Water Well Permit Requirements (Illinois statewide rule), quoted and re-checked
  9. § 153.120 Permits, Fees and Plans (LaSalle), quoted and re-checked
  10. § 153.120 Permits, Fees and Plans (LaSalle), quoted and re-checked
  11. City of LaSalle Building Department (lasalle-il.gov)
  12. § 153.045 Table of Height and Area Requirements Adopted (LaSalle), quoted and re-checked
  13. Sewage Disposal, quoted and re-checked
  14. § 51.03 Private Wastewater Disposal (LaSalle), quoted and re-checked
  15. § 151.05 Development Permit (LaSalle), quoted and re-checked
  16. Land Use Department | LaSalle County, IL, quoted and re-checked
  17. codelibrary.amlegal.com (LaSalle), 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.

Answers from the rulebook for LaSalle

LaSalle’s own rules

  • Living in an RVProhibited

    Use of a recreational vehicle or motorized home for human habitation while parked or stored on residential or commercial premises inside LaSalle city limits.

    • The code separately allows limited parking or storage of recreational vehicles in specified yards and enclosed garages, but habitation is prohibited.
    “A recreational vehicle or motorized home shall not be used for the purposes of human habitation”
  • Manufactured homesProhibited

    Mobile or manufactured-home occupancy inside the City's zoning limits.

    • The code's quoted definition treats mobile homes as structures designed for long-term occupancy with sleeping, toilet, kitchen, plumbing, and electrical facilities.
    “MOBILE HOMES, as herein defined shall not be permitted in any zoning district within the zoning limits.”
  • Septic permitRequired

    Construction of a private wastewater disposal system inside LaSalle city limits where public sanitary or combined sewer is unavailable.

    • A written permit signed by the city's authorized agent is required before construction begins.
    • The application must use the city form and include plans, specifications, and other information requested by the authorized agent.
    • A $25 permit and inspection fee is required when the application is filed.

    permit and inspection fee: 25 USD

    “Before commencement of construction of a private wastewater disposal system the owner or owners shall first obtain a written permit signed by the authorized agent. The application for such permit shall be made on a form furnished by the city, which the applicant shall supplement by any plans, specifications, and other information as are deemed necessary by the authorized agent. A permit and inspection fee of $25 shall be paid to the city at the time the application is filed.”
  • Septic inspectionRequired

    Private wastewater disposal systems constructed inside LaSalle city limits where public sewer is unavailable.

    • The authorized agent may inspect at any stage.
    • The permit holder must notify the authorized agent for final inspection before underground portions are covered.
    • Inspection is to be made within 48 hours after notice.

    inspection response time: <= 48 hours (After receipt of notice that work is ready for final inspection)

    “The inspection shall be made within 48 hours”
  • Subdividing landRegulated (with conditions)

    Subdivision of land within LaSalle city corporate limits.

    • A preliminary plan must be submitted to the Commission and then considered by the Council.
    • Required improvements and a bond are required before final plat submission.
    • The Council's approval must be endorsed before recording, and no lot may be sold until the plat is approved and recorded.
    “A preliminary plan shall first be submitted to the Commission for its consideration”
  • Building in a floodplainRequired

    Development in a floodplain inside LaSalle city limits.

    • The permit application must include scaled site drawings, existing and proposed grade information, building locations and dimensions, lowest-floor elevation where required, and project cost.
    • The Building Inspector must obtain other required federal, state, and local permits or permit-not-required letters, and may not issue the floodplain permit unless those documents are obtained.
    • Development outside the mapped floodplain may still be subject to the chapter if below base-flood elevation and hydraulically connected to a flood source.
    “shall commence any development in the floodplain without first obtaining a development permit”
  • Permit feesVariable (with conditions)

    City building-permit applications inside LaSalle city limits.

    • The fee is provided through the City of LaSalle fee schedule for contractor, building-permit, and building-inspection fees under § 124.06.
    • The reviewed section does not state the underlying schedule amounts.
    • The permit work must be completed within six months after issuance unless the Building Inspector grants a reasonable extension for good cause.

    permit validity period: 6 months (May be extended for reasonable time or times for good cause at the Building Inspector's discretion)

    “Any person and/or entity desiring a building permit shall at the time of filing application therefor pay to the city through the office of the Building Inspector a filing fee as provided within the City of LaSalle fee schedule for contractor fees, building permit fees, and building inspection fees as provided within LaSalle City Code § 124.06.”
  • Permit processPublished (with conditions)

    City building-permit applications inside LaSalle city limits.

    • Submit accurate plot plans in duplicate, drawn to scale.
    • Plans must show lot shape and dimensions, existing and proposed buildings, building lines, intended uses, and number of families or housekeeping units.
    • The original application is kept by the Building Inspector and the duplicate remains at the building during construction.
    • The lot must be based on an actual survey and staked before construction starts.
    • Permit work expires after six months unless extended for good cause.

    plot-plan copies: 2 copies · permit validity period: 6 months (May be extended for reasonable time or times for good cause)

    “All applications for building permits shall be accompanied by accurate plot plans, submitted in duplicate, drawn to scale, showing the actual shape and dimensions of the lot to be built upon, the exact sizes and locations on the lot of the buildings and accessory buildings then existing and the lines within which the proposed building and structure shall be erected or altered, the existing and intended use of each building or part of building, the number of families or housekeeping units the building is designed to accommodate, and such other information with regard to the lot and neighboring lots as may be necessary to determine and provide for the enforcement of this chapter.”

Rules another office applies inside LaSalle

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

  • Minimum lot sizeSpecified

    R-1 Single-family Residence District inside LaSalle city limits.

    • The table also specifies a minimum lot width of 60 feet.
    • Corner lots and other footnotes may modify dimensional requirements.

    minimum lot area per family: >= 7500 square feet · minimum lot width: >= 60 feet

    “R-1 Single-family Residence | 2-1/2 | 35 | 25 | 7 | 14 | 25 | 7,500 | 60”
    One more reviewed finding on this topic
  • SetbacksSpecified

    R-1 Single-family Residence District inside LaSalle city limits.

    • The table's footnote states that minimum front and rear yard depths in R-1 and R-2 are 25 feet.
    • The table lists either-side-yard width as 7 feet and aggregate side yards as 14 feet.

    front yard depth: >= 25 feet (Table footnote (9) for R-1 and R-2) · rear yard depth: >= 25 feet (Table footnote (9) for R-1 and R-2) · minimum width of either side yard: >= 7 feet · aggregate side yards: >= 14 feet

    “Minimum front and rear yard depths in R-1 and R-2 shall be 25 feet.”
  • Building heightSpecified

    AG-1 Agricultural District inside LaSalle city limits.

    • The table lists a maximum height of 2-1/2 stories and 35 feet.
    • Footnote (1) allows up to six stories and 75 feet when the additional height is set back one foot for each foot above 45 feet.

    maximum building height: 2-1/2 stories; 35 feet (Up to 6 stories and 75 feet under footnote (1) with additional setback)

    “AG-1 Agricultural | 2-1/2 | 35(1) | 30 | 7 | 14 | 35 | 7,500 | 60 [...] A building may be erected to a height of 6 stories and 75 feet back from all required yard lines a distance of 1 foot for each foot of additional height above 45 feet.”
    One more reviewed finding on this topic

Still unanswered

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

  • Owner-builder exemption — Owner-builders undertaking construction inside LaSalle city limits.
  • Inspections — Building inspections for construction inside LaSalle city limits.
  • Minimum dwelling size — Dwellings inside LaSalle city limits.
  • Lot coverage — Lot coverage inside LaSalle city limits.
  • Camping on your land — Temporary camping on private land inside LaSalle city limits.
6 more unanswered
  • Tiny homes
  • Accessory dwellings
  • Well permit
  • Agricultural exemption
  • Driveway access
  • 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 LaSalle publishes no rule on the point, not that none exists. LaSalle County’s page lists the county offices to call.

← All of LaSalle County: county rules, score and offices