ADU builders in the US
Accessory dwelling units: backyard cottages, garage conversions and in-law suites. Rules are set city by city, so local permit experience counts for more than anywhere else on the site.
- Metro areas
- 41
- Garage conversion ADU from
- $60,000
- Credentials explained
- 3
- Garage conversion ADU
- $60,000 – $150,000existing structure
- Detached ADU
- $150,000 – $400,000new build, utilities
- Prefab ADU
- $120,000 – $300,000unit, foundation, install
- Junior ADU
- $40,000 – $100,000within the main house
Typical US ranges for a mid-range project in 2026. Local figures on each city page are adjusted for regional labor rates.
ADU builders by metro area
41 metro areas, each listing up to 10 firms from Google's results for that city, ordered by Google rating weighted by review count.
Major metros
- ADU builders in New YorkNew York
- ADU builders in Los AngelesCalifornia
- ADU builders in ChicagoIllinois
- ADU builders in HoustonTexas
- ADU builders in DallasTexas
- ADU builders in San FranciscoCalifornia
- ADU builders in Washington, DCDistrict of Columbia
- ADU builders in BostonMassachusetts
- ADU builders in SeattleWashington
- ADU builders in AtlantaGeorgia
- ADU builders in DenverColorado
- ADU builders in PhoenixArizona
- ADU builders in San DiegoCalifornia
- ADU builders in AustinTexas
- ADU builders in PhiladelphiaPennsylvania
- ADU builders in San JoseCalifornia
- ADU builders in MiamiFlorida
- ADU builders in MinneapolisMinnesota
- ADU builders in NashvilleTennessee
- ADU builders in CharlotteNorth Carolina
More metros
- Orange CountyCalifornia
- ScottsdaleArizona
- PortlandOregon
- SacramentoCalifornia
- RaleighNorth Carolina
- TampaFlorida
- OrlandoFlorida
- Fort WorthTexas
- San AntonioTexas
- Las VegasNevada
- Salt Lake CityUtah
- BaltimoreMaryland
- RichmondVirginia
- PittsburghPennsylvania
- ColumbusOhio
- ClevelandOhio
- CincinnatiOhio
- DetroitMichigan
- IndianapolisIndiana
- Kansas CityMissouri
- St. LouisMissouri
Licenses and certifications explained
The licenses and certifications that matter for ADU builders, in plain English.
State or city contractor license
Legally requiredMost states license or register remodelers, and some leave it to cities. Where a license is required, working without one is illegal and usually voids your recourse. Check the number on the licensing board's own lookup.
National Association of the Remodeling Industry
The main remodeling trade body. Members agree to a code of ethics, and its Certified Remodeler (CR) designation requires experience plus an exam.
NAHB Certified Graduate Remodeler
A National Association of Home Builders designation for remodelers, covering business management, estimating and customer service.
ADU builders: common questions
Can I build an ADU on my lot?
It depends on your city and state. California, Oregon and Washington have state laws that make ADUs allowed on most single-family lots. Elsewhere it is set by local zoning, so check lot size, setback and owner-occupancy rules with your city first.