Accessory dwelling unit companies

Looking for accessory dwelling unit companies 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

ADU companies offer end-to-end solutions, often handling everything from the first sketch to the final walk-through. You need these companies if you prefer a streamlined experience where one firm takes responsibility for design, permitting, and construction. They are ideal for homeowners who want to minimize the stress of managing multiple vendors and prefer a turnkey approach to adding a secondary residence to their property.

Frequently asked in Portland

What are the disadvantages of ADUs in Portland?

Potential disadvantages in Portland include the upfront cost of construction, ensuring compliance with specific zoning and building codes, and considering the impact on your property's existing infrastructure and yard. It's also worth thinking about any potential changes to property taxes or utility expenses.

How much does an ADU cost in Oregon?

The cost of an ADU in Oregon, particularly in Portland, can range widely based on size, design complexity, and site-specific needs. Factors such as foundation requirements, utility hookups, and interior finishes significantly affect the overall price. A detailed quote will provide the most accurate cost.

What are the rules for ADUs in California?

California has state laws promoting ADUs, aiming to simplify their creation and increase housing options. These rules often set minimum standards for size and location, and can preempt some local restrictions. While different from Oregon, they reflect a growing trend in housing policy.

Is ADU allowed in Maryland?

Maryland's regulations for Accessory Dwelling Units differ by county and municipality. Some areas have adopted more favorable policies to address housing needs, while others have more stringent rules. It's essential to consult the specific local zoning ordinances for ADU permissibility.

California has established grant programs to assist homeowners with the expenses associated with building Accessory Dwelling Units, including pre-construction and soft costs. These initiatives are designed to make ADUs more accessible. Program details can vary, so checking current state resources is recommended.

What are the rules for ADU in California?

California's ADU laws generally allow their construction in many residential zones with streamlined permitting and reduced parking mandates. These state-level regulations aim to boost ADU development, though local jurisdictions can have their own specific requirements within these parameters.

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