ADU rules in Missouri
Representative cities: St. Louis, Kansas City.
ADU permit rule
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Frequently asked questions
Do I need a permit to build an ADU in Missouri?
Per Missouri rules, an ADU is "yes" for a permit and the authority is "city". ADUs require a building permit plus zoning/use approval. Missouri has no statewide residential building code, so allowance and rules are set locally (e.g., St. Louis and Kansas City each have their own requirements). Verify with your municipal building department. Always confirm with the issuing building department.
How big can an ADU be in Missouri?
Size limits for an ADU in Missouri are set by local zoning — verify with your city building department.
What are the ADU setbacks in Missouri?
Setback rules vary by city in Missouri; confirm with the local planning or building department.
How much does an ADU permit cost in Missouri?
Fee basis: Permit fees set locally by each municipality — verify with the city building department (St. Louis Building Division or KC Permits Division).