Accessory dwelling unit companies — Portland, OR

Looking for accessory dwelling unit companies in Portland, OR? Call AccessoryDwellingUnit Pros 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 is a custom project, so costs vary based on your specific choices. Site conditions are the biggest factor; if your land requires significant grading, utility extensions, or foundation work, those expenses add up quickly. Choosing high-end finishes, custom cabinetry, or complex roof lines will also push the budget higher compared to a standard design. Prefabricated units often offer predictable costs, while custom site-built structures allow for more flexibility but can be harder to estimate upfront. Exact pricing confirmed free on the call.

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Frequently asked in Portland

What are the disadvantages of ADUs in Portland?

How much does an ADU cost in Oregon?

The cost of an ADU in Oregon varies based on size, materials, and site preparation needs. Factors like existing utility connections and foundation requirements in Portland play a big role. For an accurate cost, it's best to get a personalized quote from a local ADU specialist. They'll assess your property's unique conditions.

What are the rules for ADUs in Oregon?

Is an ADU allowed in Maryland?

While this service is focused on Oregon, many areas, including Maryland, do permit ADUs. The specific regulations can differ significantly from one county or city to another. It's always recommended to consult with local ADU professionals in Maryland for the most accurate and up-to-date information.

What are the rules for ADUs in California?

California has established state laws that generally facilitate ADU construction, often with statewide guidelines. Local jurisdictions might still impose certain design or development standards. If you're considering an ADU in California, connecting with experts in that state is crucial for proper guidance.

These programs typically have specific requirements for eligibility. Although not available in Oregon, it demonstrates the types of financial support that can exist. We can help you investigate any available Portland incentives.

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: Laurelhurst, Irvington, Sellwood-Moreland, Alberta Arts District, Downtown Portland, Pearl District — and every surrounding area.