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

Note: The following state-wide building codes and regulations apply universally to all jurisdictions within Missouri, including St. Louis City.

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

Select a City in St. Louis City

If your project is located within incorporated city limits, you will likely need to follow municipal ordinances rather than county rules. Select your city below to view local regulations.

Saint Louis

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