Accessory dwelling unit cost — Portland, OR | AccessoryDwellingUnit Solutions

Looking for accessory dwelling unit cost in Portland, OR? Call AccessoryDwellingUnit Solutions 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 budget. The biggest factor is whether you choose a prefabricated unit or a custom build on-site. Site preparation is also significant; if your land requires extensive grading, utility trenching, or foundation work, costs will climb. Your choice of finishes—like kitchen cabinetry, flooring, and siding materials—also shifts the bottom line. We help you navigate these variables to find a setup that fits your property. Exact pricing confirmed free on the call.

About this service

Pricing for an ADU is driven by the quality of finishes, the foundation type, and the complexity of your site’s terrain. Projects on flat, accessible lots are generally more affordable than those requiring significant grading or utility trenching. Exact pricing confirmed free on the call.

Frequently asked in Portland

What are the disadvantages of ADUs?

Potential downsides include increased utility bills for your primary residence and the importance of managing privacy for both you and your ADU occupants. Property taxes might also be affected. It's wise to consider these aspects alongside the advantages.

How much does an ADU cost in Oregon?

What are the rules for ADUs in California?

California has robust state laws that generally simplify ADU approvals, aiming to increase housing supply by overriding local limitations on lot size and owner-occupancy. These rules promote ADU construction. Your local Oregon regulations are what matter here.

Is an ADU allowed in Maryland?

Maryland's allowance of ADUs depends on local county and city ordinances, with varying rules on size, setbacks, and parking. It's essential to confirm the specific regulations applicable to your Maryland property. This service is for Oregon.

What are the rules for ADU in California?

California's ADU legislation typically grants ADUs by right if they meet objective standards, requiring swift review and limiting impact fees. This framework facilitates easier ADU development statewide. We focus on Portland.

California has provided grants to help subsidize ADU construction, sometimes covering pre-development expenses. These programs are designed to encourage more ADUs. Details can be obtained from state housing authorities. Our service is for Oregon.

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, Pearl District, Sellwood-Moreland, Alberta Arts District, Hawthorne, Mississippi — and every surrounding area.