Adu services — Portland, OR | AccessoryDwellingUnit Services

Looking for adu services in Portland, OR? Call AccessoryDwellingUnit Services for a contact a provider — no obligation. Licensed adu builders serve Portland and the surrounding area, and you'll get straight answers on timing and what affects the price.

Last updated: September 24, 2026

What affects the price

Building an ADU involves several moving parts that shape your total investment. The final figure depends heavily on whether you choose a prefab unit or a custom build from the ground up. Site conditions are another major factor; if your property requires extensive grading, utility trenching, or foundation work, costs will climb. You also have to consider your choice of finishes, like high-end appliances or custom cabinetry. Navigating local permit fees and impact assessments also adds to the total.

About this service

ADU services manage the technical side of building a backyard cottage or garage conversion. From verifying local property setbacks to plumbing and electrical connections, these professionals handle the logistics required to make a structure legal and habitable. You should reach out for these services when you have an idea for an extra living space but need a professional to ensure the project meets all safety codes and city regulations.

Frequently asked in Portland

What are the disadvantages of ADUs in Portland?

Potential disadvantages of ADUs in Portland can include navigating the city's unique permitting process and ensuring adequate parking solutions. Construction costs can also be a consideration depending on your chosen location and design. It's beneficial to understand these aspects upfront.

How much does an ADU cost in Oregon?

The cost of an ADU in Oregon, including in Portland, depends heavily on its size, chosen materials, and any specific site challenges on your property. Factors like foundation type, utility connections, and interior finishes all impact the overall price. We can get you a precise estimate.

What are the rules for ADUs in California?

California has state laws designed to make building ADUs easier, often setting minimum standards that local jurisdictions must adhere to. These rules cover aspects like maximum size and minimum lot size. However, your project is in Oregon, so we focus on Portland's regulations.

Is ADU allowed in Maryland?

Yes, ADUs are generally permitted in Maryland, though regulations differ by city and county, including Baltimore. Key requirements often involve lot size, setbacks, and the application process. Confirming the specific rules for your Maryland property is essential.

What are the rules for ADU in California?

California has state legislation that simplifies ADU approvals by setting statewide standards that local governments must follow. This initiative aims to increase housing stock by making ADUs more accessible. Homeowners in California often find the process smoother due to these laws.

Also serving nearby: Vancouver · Beaverton · Gresham · Hillsboro · Salem

All cities in Oregon →

More on this: HUD ADU resources — ADU policy and financing research.

Service area details

630,498residents

4,723per sq mile

8ZIP codes served

Serving all of Portland — population 630,498; about 4,723 residents per square mile across 133.5 sq mi. ZIP codes covered include 97201, 97202, 97203, 97204, 97205, 97206, 97207, 97208.

Neighborhoods served in Portland: Hawthorne, Laurelhurst, Mississippi, Sellwood, Alberta Arts District, Nob Hill — and every surrounding area.