Accessory dwelling unit cost — Portland, OR | AccessoryDwellingUnit Services

Looking for accessory dwelling unit cost 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

Total costs for an ADU vary based on the size of the unit, the complexity of the site, and the quality of materials you select for the kitchen and bathroom. Things like trenching for new sewer lines or upgrading your main electrical panel can also impact the bottom line. We provide an exact pricing confirmed free on the call.

Frequently asked in Portland

What are the disadvantages of ADUs in Portland?

How much does an ADU cost in Oregon?

What are the rules for ADUs in Oregon?

Oregon has state-wide ADU standards, but Portland has its own specific zoning ordinances and building requirements. These often address aspects like lot coverage, parking, and utility connections. Understanding these local rules is crucial for a successful ADU project. The pros we partner with are well-versed in these regulations.

Is an ADU allowed in Maryland?

This page is dedicated to ADU services in Portland, Oregon. Maryland has its own set of regulations for accessory dwelling units that differ from Oregon's. If you're seeking ADU services in Maryland, you'll need to find a local provider there. We are here to assist with your Portland ADU projects.

What are the rules for ADU in California?

This page focuses on accessory dwelling units in Portland, Oregon. California has a distinct set of ADU laws and regulations that are different from those in Oregon. If you need information or services for ADUs in California, you should seek out providers in that state. We specialize in Portland-area ADUs.

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: Pearl District, Downtown, Hawthorne, Alberta Arts District, Sellwood-Moreland, Nob Hill — and every surrounding area.