Building Setbacks & Zoning in St. Charles County, MO (2026)
3 rules for unincorporated St. Charles County, Missouri.
Verified from official government sources
Setback Rules
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.
Yard Setbacks in St. Charles County
Some RestrictionsSt. Charles County Code § 405.080(D)
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 ...
Structure Height Limits
Homes in unincorporated St. Charles County's RR through R1E single-family districts cap out at forty feet unless the Board of Zoning Adjustment grants a variance. Church spires can go to one hundred feet, and wind turbines and Agricultural District brewhouses get their height set individually through a conditional use permit.
St. Charles County Structure Height Limit
Some RestrictionsSt. Charles County Code § 405.090(D)(1); § 405.410(A)-(D)
Maximum height. Forty (40) feet (except as regulated in Part 3, Article I, Section 405.405 et seq.). ... A. The height limits established in Part 2, District Regulations, may be exceeded only by variance granted by the St. Charles County Board of Zoning Adjustment; agricultural structures and stealth communication facilities/telecommunication devices added to existing structures are exempt from...
Lot Coverage Limits
St. Charles County caps impervious lot coverage at 70 percent in its High Technology Corridor District under Code § 405.165(A)(5), counting every building and every square foot of paving used for access, circulation, loading, or parking toward that limit. The Division of Planning and Zoning checks the cap against the required site development plan before an HTCD project breaks ground.
St. Charles County 70% Lot Coverage Cap
Some RestrictionsSt. Charles County Code § 405.165(A)(5)
Lot coverage. The maximum lot coverage shall not exceed seventy percent (70%). This represents that portion of the site which is covered by impermeable surfaces, such as buildings or paving for access, circulation, loading, and parking.
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