Accessory dwelling unit services — Portland, OR

Looking for accessory dwelling unit services 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

These services cover the entire lifecycle of building a backyard home, from initial property assessments and architectural design to navigating local zoning permits. You need this when you want to add living space to your property but don’t know where to start with city regulations or site feasibility. Professionals handle the paperwork, site planning, and technical requirements so you can focus on the final layout and how you plan to use the additional square footage on your lot.

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, including in Portland, varies based on size, complexity, and material choices. Factors like foundation work, utility connections, and interior finishes significantly impact the total. Despite the upfront investment, ADUs can offer a strong return through rental income. A personalized quote provides the most accurate cost estimate.

What are the rules for ADUs in California?

California has state-level legislation designed to simplify the process of building ADUs by setting minimum standards. These rules often address minimum lot sizes and owner-occupancy requirements. While many cities follow these guidelines, it's always crucial to verify local specifics. This framework encourages ADU development across the state.

Is ADU allowed in Maryland?

Yes, ADUs are permitted in many jurisdictions within Maryland, including Baltimore. However, each county and city has its own specific regulations concerning size, placement, and permitting. It's essential to research the precise rules for your area. Adhering to these local requirements is key for a successful ADU project.

What are the rules for ADU in California?

California has enacted laws to encourage ADU construction, often overriding local restrictions with statewide standards. These typically include provisions on minimum lot sizes and reduced parking requirements. While many cities have adopted these, always check your local ordinances for any additional specifics. This makes ADUs more accessible statewide.

California has previously offered various financial assistance programs for ADU projects, including grants and loans, though specifics and availability can vary. These programs aim to reduce the financial barrier to building an ADU. It's important to research current state and local funding opportunities. Consulting with ADU professionals can offer insights into available resources.

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