Kansas City allows one accessory dwelling unit by right on any lot where a detached house is the principal building, in every zoning district, under Sec. 88-305-15 of the Zoning and Development Code (Ord. 220698, passed Sept. 15, 2022; re-enacted with a height cap by Ord. 230552, June 29, 2023). A detached ADU goes in the rear yard, 5 ft from every property line, no taller than the house or 25 ft, with a footprint of at most 60% of the house's footprint or 25% of the rear yard and a floor area of at most 800 sq ft (or 90% of the house's). No extra parking is required, but the owner must live in the house or the ADU and record a deed restriction before the certificate of occupancy. The permit is a standard one- and two-family building permit through CompassKC (7-business-day review goal; about $550 in building-permit fees on a $150,000 project), and the City offers seven free pre-approved plans, including an ADU-over-garage design.
Zoning & Size Requirements [1][2][3][4][5][6][7]
Yes — Kansas City allows ADUs. A detached ADU can typically be up to 800 sq ft under current Missouri and Kansas City zoning rules.
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| Allowed Zones | Citywide: any lot where a detached dwelling is the principal building, in every zoning district (Sec. 88-305-15-B; Ord. 220698, passed 9-15-2022). Attached ADUs must sit in the rear or side yard; detached ADUs in the rear yard (88-305-15-C.1). |
| Max Size (Detached) | 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). |
| Max Size (Attached) | No separate ADU cap in the code: an attached ADU follows the lot and building standards of the principal building (88-305-15-C.6); the 800 sq ft / 90% limits in C.7 apply to detached units. It may have its own exterior entrance or a shared vestibule (C.5). Confirm with the Development Concierge before designing above 800 sq ft; the building code treats house-plus-attached-ADU as a duplex. |
| Max Size (JADU) | Not a category in Kansas City's code. The only accessory unit type is the ADU defined in 88-810-005: 'a secondary dwelling unit on the same lot as a principal dwelling unit' that may house an independent household. |
| Max Height | Detached ADU: the height of the principal building or 25 ft, whichever is less (88-305-15-C.7.a, added by Ord. 230552, passed 6-29-2023). Attached ADU: the district height limit that applies to the house (C.6). Exterior stairs to an upper-level ADU are allowed only on sides facing the interior of the lot (C.8). |
| Max Units | One ADU per lot: 88-810-005 defines an ADU as 'a secondary dwelling unit on the same lot as a principal dwelling unit', and the 2022 staff report (CD-CPC-2022-00131) describes the house plus the ADU as 'the two units'. |
Setback Requirements [1][2][3][4][5][6][7]
Kansas City requires a rear setback of about 5 ft for a detached ADU, and no additional parking is required. Owner-occupancy is required.
| Rear Setback | 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). |
| Side Setback | 5 ft including projections; on a street side yard, 5 ft or the principal building's setback, whichever is greater (88-305-15-C.7.b). |
| Front Setback | A detached ADU must be in the rear yard (88-305-15-C.1 and C.7). An attached ADU sits in the rear or side yard and keeps the house's own front setback (C.1, C.6). |
| Parking Required | None: 'No additional off-street parking is required' (88-305-15-C.3); any parking you choose to build must meet 88-420. Separately, Ord. 260219 (passed 4-9-2026) rewrote 88-420 to drop minimum off-street parking inside the Urban Core (Missouri River to 85th St, State Line Rd to the Blue River) and for houses on lots platted before 9-10-1951. |
| Owner Occupancy | Required: the owner must live in either the house or the ADU and record a deed restriction limiting occupancy of one unit to the owner; proof of recording goes to the Director of City Planning and Development before the ADU's certificate of occupancy (88-305-15-C.2). Ord. 220698 ordered a one-year review of this rule; the June 2023 re-enactment (Ord. 230552) kept it unchanged. |
| Min Lot Size | None stated in 88-305-15; the 60%-of-house / 25%-of-rear-yard footprint caps and the 88-305-02-E total accessory-building limit do the work. Since 1-1-2024 a sealed, staked survey must accompany the plans unless the structure is more than 10 ft from every property line (IB100). |
Permit Process & Fees [8][9][10][11][12]
An ADU permit in Kansas City goes through a standard permit review. Typical timeline: Plans Review's published goal for one- and two-family reviews is 7 business days per cycle (resubmittals 10 business days); allow 3-8 weeks to permit including one resubmittal (estimate). The 2x-fee priority review is not offered for one- and two-family projects. Permit fees: 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.
| Approval Process | By right, no hearing. Apply on CompassKC for a one- and two-family building permit (site plan plus sealed survey per IB100), then electrical, plumbing and mechanical permits (licensed contractors, or the owner-occupant for DIY work); record the owner-occupancy deed restriction; pass inspections; obtain the certificate of occupancy before anyone moves in. |
| Review Timeline | Plans Review's published goal for one- and two-family reviews is 7 business days per cycle (resubmittals 10 business days); allow 3-8 weeks to permit including one resubmittal (estimate). The 2x-fee priority review is not offered for one- and two-family projects. |
| Permit Fees | 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. |
| Impact Fees | No general impact fee, but the Arterial Street Impact Fee (Ch. 39, Sec. 39-4) is charged at building-permit issuance for new residential construction inside eight benefit districts (growth areas, mainly the Northland and south KC); ask the Permits Division whether your parcel is in a district and how an ADU is assessed. |
| Plan Check | Included in the building-permit review; the City calculator lists no separate residential plan-check fee. Express review by appointment under IB115; a staked, sealed survey is required with the plans since 1-1-2024 (IB100). |
| Pre-Approved Plans | Yes: 7 free Pre-Approved Housing Master Plans including an 'ADU Over Garage' and a 'Tiny House'. You still submit a site plan and survey, pull each trade permit, and have a mechanical contractor design the HVAC (IB171). |
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Construction Costs [13][14]
Building an ADU in Kansas City typically costs $90,000-$200,000 ($150-$300 per sq ft); a garage conversion runs $60,000-$150,000.
See what this means for your lot — ask Kansas City ADU builders for a quote →
| Average Build Cost | $90,000-$200,000 |
| Cost per Sq Ft | $150-$300 |
| Garage Conversion | $60,000-$150,000 |
| Prefab ADU (Installed) | $75,000-$150,000 |
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Rental Income Potential [15][16][17][18]
A 2-bedroom ADU in Kansas City rents for around $1,350-$1,550/mo, an estimated 6-10% gross (estimate).
| Avg Rent (1 Bedroom) | $1,100-$1,300/mo |
| Avg Rent (2 Bedroom) | $1,350-$1,550/mo |
| Short-Term Rental | Yes, only as a 'resident short-term rental': non-resident STRs are prohibited in every R district (88-321, Ord. 230267, passed 5-4-2023). |
| Est. Annual ROI | 6-10% gross (estimate) |
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Recent Law Changes
What's Changed Recently
- Ord. 260219 (passed April 9, 2026): 88-420 parking rewritten, no minimum off-street parking in the Urban Core; ADUs already needed none under 88-305-15-C.3
- Ord. 250965 (passed Nov 13, 2025): short-term rental registration re-enacted at $200/yr, resident-only in R districts, plus a 'major event' registration of up to 90 days for the 2026 World Cup
- Ord. 250285 (passed April 17, 2025): more housing types allowed on corner lots in R-6 districts (88-110-04 and -06); not an ADU change
- Ord. 230552 (passed June 29, 2023): 88-305-15 re-enacted to add the 25-ft/principal-building height cap, the garage-combination floor-area rule and the 88-305-02-E total-footprint reference; owner-occupancy kept
- Ord. 230267 and 230268 (passed May 4, 2023): non-resident STRs prohibited in all R districts; registration required from June 15, 2023
- Ord. 220698 (passed Sept 15, 2022): ADUs legalized citywide by right (new 88-305-15 and 88-810-005)
- 2026-09-20: entry re-verified against the authenticated ordinances (Municode is bot-walled); attached-ADU sizing, STR eligibility, permit fees, review time and impact-fee wording corrected
Tips for Building an ADU in Kansas City
- Cost basis: Tiny Terra Homes' Kansas City guide (July 19, 2026) puts a typical metro ADU at $90,000-$180,000+; Angi (May 30, 2026) gives $150-$300 per sq ft and $60,000-$150,000 for a garage conversion; the prefab range is the KC range less roughly 20%. Rents: HUD FY2026 FMR $1,197 (1BR) / $1,358 (2BR) and Zumper medians of $1,120 / $1,400 (Sept 20, 2026).
- Do the footprint math first: a 1,200 sq ft house allows at most 720 sq ft of detached-ADU footprint (60%), a 2,400 sq ft rear yard allows 600 sq ft (25%), and the smaller number wins; a detached garage shares the accessory-building total under 88-305-02-E.
- An attached ADU is not capped at 800 sq ft by 88-305-15 (it follows the house's own lot and building standards under C.6), but confirm with the Development Concierge (concierge@kcmo.org, 816-513-1511) before you design larger.
- Order the sealed, staked survey early (required since Jan 1, 2024 unless every wall is more than 10 ft from a property line) and record the owner-occupancy deed restriction before final inspection; the certificate of occupancy waits on proof of recording.
- Short-term renting the ADU works only while your primary residence stays on the parcel: register under Ch. 56 Art. VIII ($200/yr) before listing; a non-resident STR in an R district is prohibited.
- Fire-rated construction is a building-code requirement within 5 ft of a property line or 10 ft of another building, so a 5-ft-setback ADU usually needs rated walls; price that into the design.
- Cost basis (2026-09-20 re-verification): short term allowed: Yes, only as a 'resident short-term rental': non-resident STRs are prohibited in every R district (88-321, Ord. 230267, passed 5-4-2023). The registrant must keep their primary residence on the same parcel (270+ days a year, 12-month certification) and register yearly ($200; Ch. 56 Art. VIII, re-enacted by Ord. 250965, 11-13-2025).
ADU Builders in Kansas City
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Sources & References
All data on this page is sourced from official government records and verified market data. View our full methodology.
- Authenticated Ordinance 230552 (passed 6-29-2023): repeals and re-enacts Sec. 88-305-15 Accessory Dwelling Units (adds max height) - KC City Clerk/Legistar Government Data — Accessed 2026-09-20
- Ordinance 220698 committee substitute text (passed 9-15-2022): new Secs. 88-305-15 and 88-810-005 - KC City Clerk/Legistar Government Data — Accessed 2026-09-20
- Ordinance 220698 record (introduced 8-11-2022, passed 9-15-2022) - Kansas City Legistar Government Data — Accessed 2026-09-20
- City Plan Commission staff report CD-CPC-2022-00131 (ADU ordinance, 9-6-2022) Government Data — Accessed 2026-09-20
- Ordinance 260219 (passed 4-9-2026): repeal and replace Sec. 88-420 Parking and Loading - Parking Text Amendments exhibit Government Data — Accessed 2026-09-20
- KCMO Chapter 88 - Code Amendments (pending text amendments list) Planning Department — Accessed 2026-09-20
- KCMO Zoning and Development Code Sec. 88-305-15 (Municode, current codification) Government Data — Accessed 2026-09-20
- KCMO Pre-Approved Housing Master Plans (7 free plans incl. ADU Over Garage) Planning Department — Accessed 2026-09-20
- KCMO Building and Development Fee Schedule + Fee Estimation Calculator (residential permit formula) Planning Department — Accessed 2026-09-20
- KCMO Plans Review - turnaround times (one- and two-family 7 business days), IB100 survey rule Planning Department — Accessed 2026-09-20
- KCMO Electrical, Plumbing and Mechanical Permits (who may pull trade permits; CofO) Planning Department — Accessed 2026-09-20
- KCMO Development Process Guide - Arterial Street Impact Fees FAQ (Ch. 39, Sec. 39-4) Planning Department — Accessed 2026-09-20
- Tiny Terra Homes - ADU Cost Breakdown: 2026 Guide for Kansas City Owners (July 19, 2026) industry — Accessed 2026-09-20
- Angi - How Much Does an ADU Cost to Build? (updated May 30, 2026) industry — Accessed 2026-09-20
- HUD FY2026 Fair Market Rents - Kansas City, MO-KS HUD Metro FMR Area (FY26_FMRs.xlsx) Government Data — Accessed 2026-09-20
- Zumper - Kansas City, MO rent research (updated Sept 20, 2026) industry — Accessed 2026-09-20
- Authenticated Ordinance 230267 C.S. (passed 5-4-2023): Sec. 88-321 Short Term Rentals Government Data — Accessed 2026-09-20
- Authenticated Ordinance 250965 C.S. (passed 11-13-2025): Ch. 56 Art. VIII Short-Term Rental Registration Government Data — Accessed 2026-09-20
- Kansas City Legistar web API - matters with 'Accessory Dwelling' in the title (220698 and 230552 only) Government Data — Accessed 2026-09-20
Frequently Asked Questions
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