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ADU builders in Portland

The 3 ADU builders from Google's results for Portland, Oregon, ordered by Google rating weighted by review count. No firm pays to be listed or ranked.

Last updated

Garage conversion ADU
$63,500 – $159,000existing structure
Detached ADU
$159,000 – $424,000new build, utilities
Prefab ADU
$127,000 – $318,000unit, foundation, install
Portland vs US
+6%above the US median

Licensing in Oregon. Oregon contractors need a Construction Contractors Board (CCB) license, which also carries a bond.

Portland ADU

4.9(31)on GooglePortland, OR

Based in Portland, Oregon, Portland ADU builds accessory dwelling units under builder Jason Ali Allen. His building background includes work on a two-story straw bale house in Germany constructed entirely with hand tools.

(503) 756-2813 4804 NE 52nd Ave, Portland, OR 97218

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Accessory Dwelling Unit Builders in Portland & Seattle

4.6(15)on GooglePortland, OR

Hammer & Hand builds custom homes, remodels existing houses and handles commercial construction in Portland. The firm also builds passive houses and runs its own woodshop for custom cabinetry and woodworking, and it takes on additions, ADUs and design-build projects.

(503) 232-2447 1011 SE Lincoln St, Portland, OR 97214

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Dweller

No Google reviews yetPortland

Prefab accessory dwelling units are the core of Dweller's work in Portland, Oregon, with modular units assembled offsite and then placed in residential backyards. The company covers permitting, site planning and the rest of the project, and offers a deferred ownership program in which it develops and owns the unit on the homeowner's lot.

(800) 393-5537

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What ADU builders charge in Portland

In Portland, a garage conversion ADU typically costs $63,500 – $159,000. Remodeling labor in Portland runs about 6% above the US median, which accounts for most of the difference from the same project elsewhere.

How to choose between them

  • Check the license yourself. Where Oregon or Portland licenses this work, the licensing board's own lookup confirms a license number in a minute. Do it before you sign, not after.
  • Get three bids on the same scope. Written down, split into labor, materials, allowances and anything structural. Most people compare a total against a total and end up choosing between two different projects.
  • Ask what is not included. Permits, debris removal, fixture and finish allowances, and repairs after demolition are the four that turn a cheap bid into an average one.
  • Never pay a large deposit up front. A deposit to order materials and hold a start date is normal. Half the total before anyone shows up is not.

How this list is ordered

These are the firms from Google's results for "adu builders portland or", with directories, chains and suppliers removed. They are ordered by Google rating weighted by review count, and the ratings shown are Google's. No firm pays to be listed or ranked. The list was last updated in October 2026.

ADU builders in Portland: 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.