Accessory dwelling unit permit cost

Looking for accessory dwelling unit permit cost 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.

About this service

Permit fees are paid to your local municipality and fluctuate based on the specific city or county where your property is located. These costs cover plan reviews, impact fees, and safety inspections required to make your new space legal and compliant. Because every jurisdiction has a different fee structure, the final amount depends on your specific town’s regulations. We help you estimate these during the planning phase. Exact pricing confirmed free on the call.

Frequently asked in Portland

What are the disadvantages of ADUs in Portland?

How much does an ADU permit cost in Portland?

What are the rules for ADUs in Oregon?

Oregon has state laws that generally support ADU development, and Portland has embraced these with its own specific ordinances. These rules address lot size, occupancy, and design. A local professional can detail how Portland's regulations apply to your property. Call for advice.

Is an ADU allowed in Maryland?

While this service focuses on Portland, Maryland has its own specific rules for ADUs. Each county and city in Maryland will have its own set of regulations. If you're in Maryland, you'll need to research those local requirements. We can help you in Portland.

Oregon and Portland might have different financial incentives or loan programs available for ADU projects. It’s wise to investigate local and state funding opportunities. Call for advice on available programs.

What are the rules for ADUs in California?

California has implemented broad legislation to simplify ADU construction, aiming to increase housing availability. These laws often cover permitting timelines and parking standards. Local rules can still add layers of complexity. We focus on Portland's regulations. Call us.

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