Compare ADU zoning rules across 1 Missouri cities. Average ADU score: 7.0/10.
Gathered from the 1 city below, with the bill or ordinance each one names. Statewide measures are listed once with the cities they reached, rather than repeated for each.
Statewide law sets a floor; the numbers that decide your project are local. Here is the spread across the 1 Missouri city covered here, taken from each city's own ordinance rather than a state summary.
| Question | Across Missouri |
|---|---|
| Are ADUs permitted? | 1 of 1 permit them. |
| Detached size cap | Median 800 sq ft, from 800 to 800 sq ft across the 1 cities publishing a numeric cap. |
| Owner-occupancy | Required in 1 of 1. |
| Build cost | $90,000 to $200,000 depending on city and unit type. |
Recomputed whenever a city page changes, so this and the city pages below cannot disagree.
1 of the 1 Missouri city we cover permit ADUs. Whether yours is allowed depends on your city’s code and your lot; the table below links to each city.
Detached size caps run from 800 to 800 sq ft across the 1 Missouri cities that publish a number; the median is 800 sq ft. Many cities also cap an ADU at a share of the main house.
1 of the 1 cities we cover require it; the rest do not. Check the city page for yours.
$90,000 to $200,000 depending on the city and the type of unit, from each city’s own cost guide.
You apply to your city’s building department for a building permit (or to the county, if the lot is outside city limits). Each city page lists its own process, fees and published review times.
| City | Max Size | Setbacks | Permit Fees | Build Cost | 1BR Rent | Score |
|---|---|---|---|---|---|---|
| Kansas City | 800 sq ft floor area or 90% of the house's floor area, whichever is smaller (88-305-15-C.7.d). Footprint also capped at 60% of the house's footprint or 25% of the rear yard, whichever is smaller, and never more than 800 sq ft (C.7.c). An ADU in or on a garage counts the garage's floor area cumulatively (C.4), and all detached accessory buildings together must stay within 88-305-02-E (C.7.f). | 5 ft from all property lines, measured to projections such as eaves (88-305-15-C.7.b). Any other setbacks follow the accessory-structure rules of 88-305-02 (C.7.e). | Residential building permit = $483 + $1.41 per $1,000 of valuation over $100,000 (City fee calculator; Building Code Sec. 18-20): about $554 on a $150,000 ADU or $624 on $200,000, plus separate electrical, plumbing and mechanical permits. | $90,000-$200,000 | $1,100-$1,300/mo | 7/10 |
Tell us about your project and we'll pass it to ADU builders serving Missouri. Free, no obligation — you choose who to work with. We don't have builders in every area yet; if nobody covers yours, we'll email you to say so.
🔒 Your info is secure. We share it only with contractors quoting your project. No spam, no obligation.
Just browsing? Search ADU builders near you by ZIP code.
Most ADU projects are funded through HELOCs, construction loans, or cash-out refinancing. Compare rates from top lenders.
Some links on this page are affiliate links. We may earn a commission at no extra cost to you. Learn more