Winnebago County, IL Building Setbacks & Zoning: Lot Coverage Limits (2026)
Key Facts
- Single-family cap
- 40% impervious (AG/A-1/A-2)
- Other uses cap
- 60% (AG/A-1) or 65% (A-2)
- Open Space district
- 35% max, any use
- Governing table
- UDO Table 7.2, Sec. 7.7
- Applies to
- Unincorporated county land only
Summary
Winnebago County's Unified Development Ordinance limits impervious surface on single-family lots in the AG, A-1, and A-2 districts to 40% of lot area, with non-residential uses allowed up to 60% or 65%.
MAXIMUM IMPERVIOUS SURFACE Single-Family Dwelling: 40% All Other Uses: 60% Single-Family Dwelling: 40% All Other Uses: 60% Single-Family Dwelling: 40% All Other Uses: 65% 35%
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 64).
Full Breakdown
Table 7.2 of the county's Unified Development Ordinance sets bulk and yard standards for the Agricultural (AG, A-1, A-2) and Open Space (OS) districts, which cover unincorporated Winnebago County outside city limits. Under the 'Maximum Impervious Surface' row, single-family dwellings in AG, A-1, and A-2 are capped at 40% of the lot; all other uses may cover up to 60% in AG and A-1, and 65% in A-2. The Open Space district is capped at 35% overall, regardless of use. These caps sit alongside the same table's 30-foot front and corner-side yards, 10-foot interior side yard, and 25-foot rear yard, and are checked at building permit and site plan review.
Violations & Fines
Building beyond the impervious cap without an approved variance from the Zoning Board of Appeals is a zoning code violation; the county's general penalty (Sec. 1-11) allows fines up to $500 per day, with each day a separate offense, and can block issuance of a certificate of occupancy.
Frequently Asked Questions
Does this coverage limit apply inside Rockford or other cities?
What counts as impervious surface under the ordinance?
Sources & Official References
Other rules in Winnebago County
Compare Winnebago County to another location·View the Illinois building setbacks & zoning overview
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