Adu company — Portland, OR | AccessoryDwellingUnit Services

Looking for adu company 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

A professional company handles the heavy lifting, including architecture, engineering, permit submittals, and the actual construction labor. You need an experienced team when you want to ensure your unit is built to code, structurally sound, and completed on a predictable schedule. We act as your single point of contact, coordinating every trade and inspection so you aren't managing subcontractors yourself. We provide professional oversight from start to finish. Exact pricing confirmed free on the call.

Frequently asked in Portland

What are the disadvantages of ADUs in Portland?

While ADUs offer many benefits in Portland, potential disadvantages include the upfront construction costs and the impact on your existing yard space. You'll also need to consider the effect on your property's privacy. Navigating permitting processes can sometimes take time, though Portland is generally ADU-friendly.

How much does an ADU cost in Oregon?

What are the rules for ADUs in California?

California has specific statewide ADU laws designed to encourage their development, but local ordinances still apply. These rules often cover setbacks, lot coverage, and parking requirements. It's crucial to check the specific regulations in your city or county. This ensures your project complies with all legal mandates.

Is ADU allowed in Maryland?

Yes, ADUs are permitted in many areas of Maryland, including Baltimore. However, local zoning laws dictate the specifics, such as minimum lot sizes, setback requirements, and owner-occupancy rules. It’s essential to consult your local planning department or a specialist for precise information.

What are the rules for ADU in California?

California has offered various grant programs to help homeowners build ADUs, including programs that have provided significant financial assistance. These grants aim to make ADUs more accessible. Eligibility criteria and funding availability can change, so it's wise to research current programs.

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, Downtown Portland, Hawthorne District, Pearl District, Sellwood-Moreland — and every surrounding area.