St. Clair County, IL Building Setbacks & Zoning: Setback Rules (2026)
Key Facts
- SR-1 front/street-side yard
- 25 ft each
- SR-1 side yards
- 30 ft total, 15 ft min each
- SR-2 side yards
- 25 ft total, 10 ft min each
- SR-3 side yards
- 15 ft total, 5 ft min each
- Rear yard depth (SR-1/2/3)
- 25 ft
- Commercial front yard (HB, B-1, B-2)
- 75 ft
- Setback violation penalty
- $50-$500 fine, Class B misdemeanor
Summary
Unincorporated St. Clair County sets minimum yard setbacks by zoning district in Zoning Code Section 40-3-7. Every agricultural and residential district, from "A" Agricultural through "SR-3" Single Family Residence, carries a 25-foot front yard and a 25-foot side yard facing a street; only rear and side yard minimums shrink as lot size drops, from 40 feet of combined side yard in the "A" district to 15 feet in "SR-3." The Zoning Administrator enforces the table.
40-3-7 MINIMUM AREA, BULK, YARD REQUIREMENTS ... 4 SR-1 1 per 20,000 sq. ft. 20,000 sq. ft. 100' 150' 25' 25' 30 15 ... 5 SR-2 1 per 15,000 sq. ft. 15,000 sq. ft. 100' 125' 25' 25' 25 10 ... 6 SR-3 1 per 10,000 sq. ft. 10,000 sq. ft. 75' 100' 25' 25' 15 5 ... 4 30' 25' 20% 35' 25' 10' 60' 25' 5' 5' ... 5 20' 25' 20% 35' 25' 10' 60' 25' 5' 5' ... 6 15' 25' 20% 35' 25' 10' 60' 25' 5' 5' ... Note 3: 25' if abutting "A", "RR", "SR", "MH", "MR", or "NB"; otherwise 0' or a minimum of 12' ... 40-2-2 SELECTED DEFINITIONS ... "YARD, FRONT": A yard extending across the full width of the lot between the front lot line and nearest line or point of the principal building. ... "YARD, SIDE": A yard extending from the front yard to the rear yard between the side lot line and the nearest line or point of the building. ... "YARD, REAR": A yard extending across the full width of the lot between the rear lot line and the nearest line or point of the principal building.
Full Breakdown
The table splits lot size and setbacks by district. "A" Agricultural, "RR-3," and "RR-1" each require 40 feet of combined side yard with 15 feet minimum on either side and a 25-foot rear yard. "SR-1," the district behind the county's most common single-family lots at 20,000 square feet minimum, needs 30 feet combined side yard with a 15-foot minimum per side; "SR-2" (15,000 square feet) drops to 25 feet combined with a 10-foot minimum; "SR-3" (10,000 square feet) needs only 15 feet combined with a 5-foot minimum per side.
" Section 40-2-2 defines "Yard, Front" as the space across the full lot width between the front lot line and the nearest point of the principal building, "Yard, Side" as running between the side lot line and the building from front yard to rear yard, and "Yard, Rear" as the space across the full lot width between the rear lot line and the building. Commercial and industrial districts (Highway Business, B-1, B-2, I-1, I-2) instead carry a 75-foot front yard, with side yards reduced under Note 3 to zero feet or a 12-foot minimum unless the lot abuts an "A," "RR," "SR," "MH," "MR," or "NB" district, which restores the 25-foot buffer.
A property owner who cannot meet the table may apply to the Zoning Board of Appeals for an area/bulk variance under Sections 40-11-19 through 40-11-22; the Board must find undue practical difficulty not caused by the owner, no reasonable alternative, and that the variance is the minimum deviation needed to allow reasonable use.
Violations & Fines
Building without meeting Section 40-3-7's setbacks is a Class B misdemeanor under Section 40-11-10, punishable by a fine of $50 to $500 plus costs, with each day the violation continues counted as a separate offense; the County may also pursue any other lawful action needed to secure compliance. The Zoning Administrator may act without notice or hearing under Section 40-11-7 when a violation poses an imminent peril to life or property, and any resident may file a written complaint under Section 40-11-8 to trigger an investigation.
Frequently Asked Questions
What is the front yard setback in the SR-1 district?
How wide do side yards have to be in unincorporated St. Clair County?
Can a property owner get a smaller setback than the code requires?
What happens if a structure violates the setback table?
Do commercial and industrial districts follow the same front yard rule as residential districts?
Sources & Official References
Other rules in St. Clair County
Compare St. Clair County to another location·View the Illinois building setbacks & zoning overview
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