Building Setbacks & Zoning in St. Louis County, MO (2026)
3 county-level rules, plus city-specific rules for 1 city in St. Louis County, Missouri.
Verified from official government sources
Setback Rules
Structure setbacks in unincorporated St. Louis County shrink as zoning density rises. The county's largest-lot residential district, R-1, holds buildings 30 feet off any road right-of-way and 15 feet off side or rear lines, while the denser R-6A district cuts those minimums to 20 feet in front and as little as 5 feet on the side for single-family homes.
St. Louis County Yard Setback Minimums
Some RestrictionsSt. Louis County Code § 1003.111.7(3)-(4)
(3)Minimum structure setback requirements: General.(a)Front structure setbacks. No structure shall be allowed within thirty (30) feet of any roadway right-of-way line.(b)Side and rear structure setback. No structure shall be allowed within fifteen (15) feet of any property line other than a roadway right-of-way line.(4)Specific structure setback regulations and exceptions.(a)Notwithstanding any...
Structure Height Limits
Height limits climb with zoning density in unincorporated St. Louis County. The R-1 Residence District caps dwellings at three stories or 45 feet, whichever is less, and non-dwelling structures at 60 feet, while the denser R-6A district allows dwellings up to four stories, including a basement level, before hitting the same 60-foot ceiling on other structures.
St. Louis County Residential Height Limits
Some RestrictionsSt. Louis County Code § 1003.111.6
6.Height limitations for structures. Other than telecommunication towers the maximum height of structures in the "R-1" Residence District shall be as set out below:(1)No building elevation of any dwelling structure or building accessory to a dwelling structure shall exceed three (3) stories or forty-five (45) feet in height, whichever is less.(2)No accessory building shall be taller than the pr...
Lot Coverage Limits
St. Louis County does not cap the total footprint of a single-family house on its lot, but it does cap everything else built around it. Detached accessory structures like sheds, garages, and pool houses may cover no more than 7% of the lot in every residential district, while commercial C-3 parcels face a flat 25% building-coverage ceiling.
St. Louis County Accessory Structure Lot Coverage
Some RestrictionsSt. Louis County Code §§ 1003.111.4.B(1)-(3), 1003.135.8(1)
B.Detached above-ground accessory structures shall be subject to the following design criteria:(1)Detached above-ground accessory structures shall not cover more than a total of seven (7) percent of the lot area.(2)Any detached accessory structure...may be up to four hundred (400) square feet in area, or fifty (50) percent of the building footprint of the primary structure, whichever is greater...
Building Setbacks & Zoning by City in St. Louis County
1 cities in St. Louis County have their own building setbacks & zoning rules. Each link goes to that city's dedicated page with code citations.
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