ADU Rules in Kansas City, Missouri

Kansas City, Missouri (KCMO) is the largest city in Missouri and spans portions of Jackson, Clay, and Platte counties. ADU (Accessory Dwelling Unit) regulations in KCMO are governed entirely by the city's local Zoning and Development Code — Missouri has enacted no statewide ADU preemption law, so local rules control.

Missouri/Kansas State Line Note

The Kansas City metropolitan area straddles the Missouri–Kansas state line. Kansas City, Missouri and Kansas City, Kansas are two distinct cities in two separate states. This guide covers KCMO only. If your property is in Kansas City, KS (Wyandotte County), contact the Unified Government of Wyandotte County/Kansas City, KS for applicable zoning rules.

Permitted ADU Types

Kansas City, MO generally permits the following ADU types in residential districts:

• Detached ADU: A freestanding structure separate from the primary dwelling, located in the rear or side yard.
• Attached ADU: An addition to or conversion of an attached portion of the primary structure.
• Interior/Basement Conversion: Converting existing interior space (basement, attic, etc.) within the primary dwelling into a separate unit.
• Garage Conversion: Converting an existing attached or detached garage into a living unit.

Permitted ADU types vary by base zoning district (R-1 through R-6 and beyond). Consult the Zoning and Development Code or contact the Planning & Development Department for district-specific rules.

Size, Setbacks, and Height

Specific dimensional standards — including maximum ADU square footage, minimum setbacks from property lines, and maximum height — are set by the base zoning district. As a general guide:

• Maximum size: Typically capped at a percentage of the primary dwelling's floor area or a fixed square footage limit per district standards; verify with planning staff.
• Setbacks: Rear and side setbacks for accessory structures typically range from 3 to 5 feet; front setback compliance with primary zone required.
• Height: Detached ADUs are generally limited to one story or the height standard for accessory structures in the applicable district.

Always confirm current dimensional standards with the City Planning & Development Department, as code amendments may affect your property.

Flood Zone Considerations

Kansas City sits at the confluence of the Missouri River and the Kansas (Kaw) River. Properties in or near these floodplains — including areas along the Blue River — may lie within FEMA Special Flood Hazard Areas (SFHA). ADUs in flood zones must meet additional elevation and floodproofing requirements under KCMO's floodplain management ordinance and FEMA NFIP standards. Check FEMA's Flood Map Service Center (msc.fema.gov) and confirm your property's flood zone status before planning.

Permit Process

1. Check zoning: Confirm your property's base zoning district using the KCMO online zoning map at kcmo.gov.
2. Pre-application meeting: Schedule an optional (but recommended) pre-application meeting with the City Planning & Development Department.
3. Submit building permit application: File plans with the Development Services Division. Include site plan, floor plan, elevations, and applicable engineering.
4. Plan review: City staff reviews for zoning compliance, building code, and any overlay district requirements (floodplain, historic, etc.).
5. Permit issuance: Once approved, obtain the building permit before beginning construction.
6. Inspections: Schedule required inspections (foundation, framing, electrical, plumbing, final) through the city's inspection scheduling system.
7. Certificate of Occupancy: Obtain a CO before occupying the ADU.

Contact Information

Kansas City City Planning & Development 414 E. 12th Street, Kansas City, MO 64106 Phone: (816) 513-1500 Website: kcmo.gov/city-hall/departments/city-planning-development

Disclaimer: Zoning regulations change frequently. Always verify current ADU rules directly with the Kansas City City Planning & Development Department and consult a licensed architect or contractor before beginning any project. This page is for informational purposes only and does not constitute legal or zoning advice.