An ADU builder in Kansas City is a licensed contractor who designs and constructs accessory dwelling units — detached backyard units, garage conversions, attached additions, and junior ADUs (JADUs). Because an ADU is a complete second dwelling, the builder coordinates foundation, framing, plumbing, electrical, and HVAC work and pulls it through Kansas City's permit process and utility connections. Not every general contractor has built one, so the right builder is one with ADU-specific experience in Missouri.
What ADU Builders Cost in Kansas City [13][14]
Based on our Kansas City cost data, expect the following ranges from local ADU builders. Quotes for the same scope typically vary 20-40% between contractors, so getting at least three bids is the single best way to control cost.
| New Detached ADU (all-in) | $90,000-$200,000 |
| Cost per Sq Ft | $150-$300 |
| Garage Conversion | $60,000-$150,000 |
| Prefab / Modular ADU (installed) | $75,000-$150,000 |
| City Permit & Plan Review | 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. |
For a full line-item breakdown, see our Kansas City ADU cost guide. To confirm what you're allowed to build before you hire, review the Kansas City ADU rules (max detached size: 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).; 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.).
Get Free ADU Quotes in Kansas City
Tell us about your project and we'll pass it to ADU builders serving Kansas City. 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.
Takes about a minute.
Up to 5 independent local ADU builders — never more, and we tell them nothing you don't submit here.
Compare quotes, verify license & insurance, hire (or don't). No spam either way.
🔒 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.
How to Vet an ADU Builder in Kansas City
- License: Confirm a current contractor's license in Missouri and that it's in good standing. Ask for the license number and verify it with the state board.
- ADU-specific experience: Ask how many ADUs they've completed in or near Kansas City and request addresses or photos. ADU permitting and setbacks differ from a kitchen remodel.
- Portfolio & references: Get references from recent ADU clients and, if possible, visit a finished unit.
- Insurance: Verify general liability and workers' compensation coverage. Ask for a certificate of insurance.
- Written, detailed bid: Insist on an itemized, fixed-price or clearly-scoped bid — not a verbal estimate. It should state whether permits (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.), 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).), and 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.) are included.
- Permit handling: Confirm they manage Kansas City's permit 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.", typically 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.) and who is responsible if revisions are required.
- Payment schedule: Avoid large upfront payments. A reasonable schedule ties payments to completed milestones.
Questions to Ask Before You Hire
- How many ADUs have you built in Kansas City in the last two years?
- Is your bid fixed-price, and what would trigger a change order?
- Are permits, plan check, and utility connection fees included?
- What's a realistic timeline, including permit review (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.) and construction?
- Who is my point of contact and how are delays communicated?
- What warranty do you provide on workmanship?
- Can you share three recent Missouri ADU client references?
Finance Your ADU Project
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
Are you an ADU builder? Get Kansas City leads
Homeowners on this page submit real ADU project requests in Kansas City. Each one goes to up to five local builders — that is what the homeowner agrees to — so claiming never takes it from anyone and there is no bidding. In practice far fewer ever make contact, which is why the number is five rather than three. A flat $50 only on the leads you accept: no subscription, no contract, and you deal with the homeowner directly.
Get Kansas City ADU Leads →Frequently Asked Questions
How much do ADU builders charge in Kansas City?
How do I find a good ADU builder in Kansas City?
Do ADU builders in Kansas City handle permits?
How long does it take to build an ADU in Kansas City?
Get Free ADU Builder Quotes in Kansas City
Compare bids from experienced local Kansas City ADU builders. Free, no obligation.
Get Free Quotes →