Shed Permit in St. Louis, MO
Permit Summary
Do You Need a Shed Permit?
Exemptions
Under the current Residential Code, a small detached accessory building such as a utility, storage, or tool shed, cabana, or play house can be exempt from a building permit when it is 120 square feet or less, less than 12 feet high, placed on and anchored to a minimum 4-inch-thick concrete slab, and maintains required zoning setbacks. This exemption does not cover barbecue or smoke houses, fuel or hazardous-material storage, structures containing fuel-fired equipment, or other uses presenting increased fire hazard or nuisance; a permit is required for buildings housing those uses when they exceed 50 square feet. Separate historic or floodplain approvals can still apply.
Attached Shed Rules
The 120-square-foot, under-12-foot exemption is expressly limited to detached accessory buildings. A shed attached to a dwelling or another building falls outside that detached-building exemption and must be reviewed under the applicable building-permit rules for the proposed work.
Shed Use Rules
The exemption covers ordinary small detached accessory buildings such as utility, storage, and tool sheds, cabanas, and play houses. It excludes barbecue or smoke houses, fuel or hazardous-material storage, structures containing fuel-fired equipment, and other uses that present an increased fire hazard or nuisance to adjoining property; buildings housing those excluded uses require a permit when they exceed 50 square feet.
Zoning & Placement Rules
Zoning Rules
All sheds must comply with the Zoning Ordinance, including required setbacks, even when the building-permit exemption applies. The Zoning Section reviews building-permit applications for zoning compliance. Applicable use, placement, dimensional, and overlay rules depend on the parcel's zoning district and site conditions; a zoning denial may be revised or appealed through the applicable City process.
Setback Rules
There is no single shed setback stated on the City's current general guidance. Required front, side, and rear yards depend on the parcel's zoning district and can vary with lot and structure conditions. A shed using the building-permit exemption must still maintain the setbacks required by the Zoning Ordinance, and permitted sheds are reviewed by the Zoning Section for compliance.
Maximum Height Rules
Less than 12 feet is the height condition for the small detached-shed building-permit exemption. For sheds that require a permit, the allowable height is governed by the applicable zoning district and site-specific rules; the current zoning code uses district-specific height standards rather than one citywide shed maximum.
Special Area Rules
Properties in a City Historic District or designated as a City Landmark require Cultural Resources review for exterior work, and the City states that a building permit is required in most such cases even when the Building Code would not otherwise require one. Construction in a FEMA-designated flood area requires a Floodway Development Permit even when a building permit is not required. Zoning overlays, Special Use Districts, Planned Unit Developments, Community Unit Plans, redevelopment areas, and other special conditions can trigger additional review.
Construction Requirements
Foundation Rules
To qualify for the small detached-shed permit exemption, the shed must be placed on and anchored to a concrete slab at least 4 inches thick. A shed requiring a building permit must have its proposed foundation and structural construction shown in the submitted construction documents and comply with the applicable adopted code.
Fire Separation Rules
For residential accessory structures subject to the Residential Code, the City's amended exterior-wall table applies fire-separation controls based on distance to the property line. Exterior walls at a fire-separation distance of 3 feet or less require a 1-hour rating from both sides; openings are prohibited at less than 3 feet and limited at 3 feet, and projections and penetrations near the lot line are also restricted. Greater separation generally reduces these fire-resistance restrictions.
Permit & Review Path
Permit / Review Path
A qualifying detached shed can use the no-building-permit path when it is 120 square feet or less, less than 12 feet high, anchored to a minimum 4-inch concrete slab, meets zoning setbacks, and is not an excluded higher-hazard use. Otherwise, apply for a Building Permit online or in person. The City assigns the application to the agencies needed for the project, including zoning review; after all assigned approvals are complete, the applicant pays the permit fee and receives the permit. Separate trade or special-area approvals apply when triggered.
Trade Permits & Professional Design
Trade Permit Rules
Separate electrical, plumbing, or mechanical permits may be required when the shed project includes those systems or work. The appropriate licensed contractor must apply for the applicable trade permit, and the online building-permit application can associate required plumbing, electrical, or mechanical permits.
Professional Design Rules
Professional design is not a blanket requirement for every residential shed. The Residential Code requires Missouri-licensed design professionals where state licensing law requires professional architecture or engineering, while allowing exceptions for certain one- and two-family dwelling documents and owner-prepared documents for an owner-occupied one- or two-family dwelling. The building official may also require a Missouri-licensed design professional for unusual design or construction magnitude or other work needing professional services.
What You Need Before Applying
Requirements
First determine whether the detached-shed exemption applies. If it does not, obtain a City Building Permit before construction, submit the required project information and plans, and satisfy applicable building and zoning requirements. Zoning, trade permits, historic-resource review, floodplain approval, or other agency review may also apply depending on the site and scope.
Required Documents
For a building-permit application, the City requires at minimum the project address, project plans, the $25 application fee, and an owner authorization letter when the applicant is not the owner of record. The Residential Code also requires the application to describe the work and intended use or occupancy, state the estimated construction cost, and include construction documents and other information required by the building official. In-person applications should bring five plan copies; online applications accept the file types listed by the City.