St. Charles County, MO Building Setbacks & Zoning: Setback Rules (2026)
Key Facts
- Front yard (A District, 5+ acre lot)
- 50 feet
- Side yard (A District, 5+ acre lot)
- 40 feet
- Rear yard (A District, 5+ acre lot)
- 50 feet
- Front/rear yard (lot under 1 acre)
- 25 feet
- Side yard (lot under 1 acre)
- 7 feet
Summary
St. Charles County's Agricultural District requires 50-foot front and rear yard setbacks and a 40-foot side yard setback for standard 5-acre lots.
D. Height, Area And Lot Requirements. 1. Maximum height. Forty (40) feet... 2. Minimum front yard. Fifty (50) feet. 3. Minimum side yard. Forty (40) feet. 4. Minimum rear yard. Fifty (50) feet... 8. Minimum front yard for lots of record less than one (1) acre in size. Twenty-five (25) feet. 9. Minimum side yard for lots of record less than one (1) acre in size. Seven (7) feet. 10. Minimum rear yard for lots of record less than one (1) acre in size. Twenty-five (25) feet.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: rev 4863880; v61 updated 2026-05-11; through 05-11-2026).
Full Breakdown
The Unified Development Ordinance sets zone-specific yard minimums rather than one countywide number. In the "A" Agricultural District the standard minimums are a 50-foot front yard, 40-foot side yard, and 50-foot rear yard on the base 5-acre lot. Smaller lots of record under one acre get reduced minimums: 25-foot front yard, 7-foot side yard, and 25-foot rear yard. Other districts (R1, R3A, R3B, C, I) carry their own separate yard tables in the same chapter.
Violations & Fines
Building within a required setback without a variance from the Board of Zoning Adjustment risks a stop-work order and removal or relocation of the encroaching structure at the owner's expense.
Frequently Asked Questions
Do setbacks vary by lot size in St. Charles County?
Can I get a setback exception?
Sources & Official References
Other rules in St. Charles County
Compare St. Charles County to another location·View the Missouri building setbacks & zoning overview
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