McLean County, IL Building Setbacks & Zoning: Lot Coverage Limits (2026)
Key Facts
- Governing section
- Zoning Code § 350-36.D(4)
- Max lot coverage, R-1
- 35%
- Max lot coverage, R-2
- 40% (§ 350-37D(4))
- Accessory area, lots ≤0.74 acre
- 1,500 sq ft
- Accessory area, lots ≥1.5 acres
- 2,400 sq ft
- Enforcing office
- Dept. of Building and Zoning
Summary
Single-family lots in McLean County's R-1 Single-Family Residential District cannot exceed 35% lot coverage under Zoning Code Section 350-36D(4), with accessory building area additionally capped on a sliding scale from 1,500 to 2,400 square feet depending on lot size.
Maximum lot coverage: 35%. Total area of accessory buildings, including attached garages, shall not exceed the following: On lots 0.74 acre or less: 1,500 square feet. On lots 0.75 acre to 0.99 acre: 1,725 square feet; On lots 1.00 acre to 1.49 acres: 1,950 square feet; On lots 1.5 acres or more: 2,400 square feet.
Full Breakdown
Section 350-36D(4) sets a flat 35% maximum lot coverage ceiling for every parcel in the R-1 District, then layers on a second, size-tiered limit specifically for accessory buildings, including attached garages. 5 acres or more get 2,400 square feet. This provision sits inside the same intensity-of-use block that fixes R-1 minimum lot area at 22,500 square feet for septic-served lots or 12,000 square feet for lots on public sewer and water, with a three-acre maximum lot size, so the 35% coverage cap and the accessory-area table apply on top of those baseline dimensions.
The neighboring R-2 Two-Family Residential District, by contrast, allows a higher 40% maximum lot coverage under Section 350-37D(4), using the identical accessory-building tier table. Both figures are administered by the McLean County Department of Building and Zoning as part of site plan and building permit review, and both apply only to unincorporated county land since Bloomington and Normal set their own coverage limits under their separate municipal zoning codes.
Violations & Fines
Exceeding the 35% lot coverage cap or the tiered accessory-building area limits in the R-1 District is a zoning violation. The Director of Building and Zoning can deny a building permit application that would push a lot over these limits, and construction completed without a compliant permit is subject to a stop-work order and removal or modification to bring the site back within the coverage and accessory-area standards of Section 350-36D(4).
Frequently Asked Questions
What is the maximum lot coverage in McLean County's R-1 District?
Does the accessory building area limit count against the 35% lot coverage cap?
Does the R-1 lot coverage limit apply inside Bloomington or Normal?
Sources & Official References
Other rules in McLean County
Compare McLean County to another location·View the Illinois building setbacks & zoning overview
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