Permit Requirements for Saint Louis, Missouri
For home remodeling and renovation projects in Saint Louis, determining the correct permitting authority depends on whether the project site is located within the incorporated city limits or in an unincorporated area of St. Louis city.
Authority Having Jurisdiction (AHJ)
The governing body responsible for issuing building permits, reviewing plans, and conducting inspections varies depending on exactly where the property sits in St. Louis city:
- Within City Limits: The Saint Louis Building Department typically oversees all Saint Louis building, trade, and safety permits.
- Unincorporated Areas: Properties located outside of official Saint Louis boundaries are generally governed by the St. Louis city Building & Safety Division.
Common Remodeling Permit Triggers
Remodeling is a broad category, and permit requirements depend heavily on the scope of your work. While cosmetic updates—such as painting, installing new flooring, or replacing like-for-like kitchen cabinets—generally do not require approval in Missouri, you will almost certainly need a permit for the following:
- Space Conversions: Altering non-living spaces (such as finishing a basement, finishing an attic, or converting a garage) into habitable living areas.
- Structural Changes: Removing, adding, or modifying load-bearing walls, headers, or the roofline.
- Demolition: Extensive interior renovations or "gutting" a space often requires a specific demolition permit prior to or concurrent with the standard building permit.
- Systems Alterations: Rerouting plumbing pipes, adding new electrical circuits, or moving HVAC ductwork.
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Note: Always consult the appropriate Saint Louis or St. Louis city Authority Having Jurisdiction (AHJ) before beginning demolition or construction to ensure compliance with Missouri amendments to the International Existing Building Code (IEBC) and avoid retroactive permitting fines.
Help Us Improve This Guide
If you have found a direct link to the official permit portal or a specific Saint Louis or St. Louis city ordinance for renovations, please submit an update.
Because Saint Louis is located within St. Louis City, the following broader county regulations may also apply to your project:
Missouri, St. Louis City Remodeler Permit Regulations and County Ordinances for Unincorporated Areas
St. Louis City and County Remodeling and Renovation Permit Requirements
1. Authority Having Jurisdiction: Building & Safety Division
For St. Louis City, the Building Division is responsible for enforcing the city building code, issuing building permits, and conducting inspections. For St. Louis County, permit applications are generally submitted through the county's online permitting system, with specific departments handling different aspects of code enforcement and permitting.
2. Properties in Unincorporated Areas
St. Louis County's permitting requirements apply to properties in unincorporated areas. Residents within incorporated municipalities in St. Louis County should contact their respective municipal officials for specific permit requirements, as these municipalities may contract with the county for services or handle them independently.
3. Permit Triggers for Demolition Work
A demolition permit is required for the demolition of any structure in both St. Louis City and St. Louis County. This includes detached accessory structures, towers, and in-ground pools. For St. Louis City, owners may be issued a demolition permit for small structures (e.g., garages, sheds) under certain size and height limitations. Contractors must be certified by the City of St. Louis to obtain demolition permits. In St. Louis County, a demolition application is required for any structure 120 square feet or larger, with an application fee. Owner-occupied residential property owners performing their own demolition may be exempt from this fee. Prior to demolition, utility disconnections must be verified, and in structures built before 1978, an asbestos survey is typically required.
4. Permit Requirements for Converting Non-Living Spaces
Converting non-living spaces such as garages, attics, or unfinished basements into habitable living areas generally requires a building permit in both St. Louis City and St. Louis County. This type of work involves significant alterations and changes to the building's structure and intended use, necessitating review for code compliance and safety. Specific requirements may include detailed plans, structural assessments, and ensuring compliance with egress, ventilation, and other habitability standards.
Resources to Learn More
The following statewide building codes and regulations apply universally to all jurisdictions within Missouri:
Missouri Remodeler Legislation, Codes, and Guidelines
Missouri State-Level Building Codes and Legislation for Remodelers and Residential Renovations
Missouri does not have a single, statewide building code. Instead, building codes are adopted and enforced at the local level by municipalities and counties. These local jurisdictions typically reference model codes from the International Code Council (ICC). The most commonly adopted versions of these codes in Missouri include the 2015 editions of the International Building Code (IBC), International Residential Code (IRC), International Existing Building Code (IEBC), International Plumbing Code (IPC), and International Mechanical Code (IMC). Some areas may also reference the 2009 International Energy Conservation Code (IECC) and the National Electrical Code (NEC), which are enforced locally. It is crucial for remodelers to verify the specific codes and any local amendments in effect with the local building department for their project's location. Some municipalities, like O'Fallon and Town and Country, have adopted the 2021 or 2024 editions of the International Existing Building Code, respectively.
The primary state board or agencies that set these standards are not centralized at the state level for building codes. Instead, the Division of Professional Registration supports various professional licensing boards and commissions responsible for regulating professions within the state. However, for building codes, enforcement and adoption are primarily handled by local building departments and officials.
Generally, the classification of remodels and when demolition guidelines apply are determined by local ordinances and the adopted building codes. The International Residential Code (IRC) and International Existing Building Code (IEBC) provide frameworks for alterations and repairs. Structural alterations, such as converting attics or basements to habitable spaces, typically require permits and are subject to more stringent requirements than cosmetic remodels. Demolition guidelines are also locally enforced and often require specific permits, advance notice to neighbors, and adherence to safety and debris removal protocols. For instance, some municipalities require a notice of intention to demolish to be sent to properties within 200 feet, and demolition must proceed continuously and be completed within a specified timeframe.
Missouri law broadly defines remodeling as any work that erects, demolishes, alters, or repairs improvements to a property. This includes kitchen and bathroom renovations, room additions, structural changes, and electrical, plumbing, and HVAC upgrades. For substantial renovations, Missouri statute defines it as modifications affecting at least fifty percent of the square footage of a building or costing at least fifty percent of the building's fair market value.
Resources to Learn More