Skip to main content Skip to content Detached and attached ADUs, garage and basement conversions, and rental or multigenerational suites, built to Portland’s permissive ADU code. Woodland Construction Group designs and builds accessory dwelling units across the city, one accountable team from first sketch to final walkthrough.
Review the City of Portland ADU permitting requirements before you begin.Planning an ADU in Portland, Oregon? Few cities make it easier. An accessory dwelling unit turns underused yard, garage, or basement space into a fully independent home with its own kitchen, bathroom, and entrance, and Portland’s code allows them on most residential lots. It is one of the most valuable things you can build on land you already own.
It can generate rental income in one of the region’s tightest rental markets, house aging parents or adult children, or serve as a private home office, and the same unit can shift between those roles over the years. Because ADUs involve Portland’s zoning rules, code, and full systems, the contractor you choose controls the outcome.
The right partner navigates Portland’s ADU rules and Bureau of Development Services permitting, protects your budget, and delivers a unit that is rentable, livable, and built to last for decades.
An ADU in Portland typically runs $120,000 to $350,000+ in 2026, or about $150 to $400 per square foot, depending on type, size, and finish level. New detached backyard units sit at the higher end, while garage and basement conversions cost less since the structure already exists, an option Portland’s housing stock makes especially common.
Because Portland has some of the most ADU-friendly zoning in the country, with historic fee waivers and allowances for more than one unit per lot, plus a tight rental market, an ADU here combines income, flexibility, and added property value, making it one of the highest-return projects you can build.
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An ADU is one of the few projects that earns its keep, and Portland’s rental demand makes that especially true. Rented as a long-term unit, it generates steady monthly income that offsets the build cost over time, while adding significant resale value to your property. You are building an asset, not just a room.
The 2026 Portland ADU is also about flexibility. The same backyard cottage can house aging parents close by, give adult children independence in an expensive city, welcome guests, or serve as a quiet home office, then become a rental when your needs change. Few additions adapt to a family’s life the way an ADU does.
Pair that income and flexibility with Portland’s nation-leading ADU zoning, and a well-built unit delivers both immediate utility and strong long-term value. Converting an existing basement instead? See our basement remodeling page.
Woodland Construction Group – 18 Years Experience – Portland, Oregon
Our team of licensed contractors specializes in detached and attached ADUs across the Portland metro, navigating Portland’s ADU zoning, permitting, and inspections from first sketch to final walkthrough.
An ADU turns underused yard, garage, or basement space into an income-producing home on land you already own, and in Portland’s permissive, rental-hungry market it combines income, family flexibility, and added property value better than almost anywhere.
Six ADU paths show up most often across Portland. Each one is a fully independent dwelling, engineered to meet the city’s ADU code and built to last, not a converted shed.
Standalone backyard cottages with their own foundation, kitchen, bath, and entrance, the classic Portland ADU, designed as a true second home that maximizes privacy and rental value.
Units connected to the main house, sharing a wall but fully independent, an efficient way to add a dwelling on Portland’s narrower inner-city lots.
Turning a detached Portland garage into a legal ADU, using the structure you already have to lower cost while delivering a comfortable, code-compliant home.
Converting a full basement into a separate-entrance ADU, common under Portland’s older homes, with waterproofing, egress, and full systems engineered for the city’s wet climate.
Units designed to meet Portland code as fully independent dwellings, so they are legally rentable and generate steady income that offsets the build over time.
Comfortable, accessible suites for aging parents or adult children, a practical answer to Portland’s housing costs that gives everyone independence and privacy while keeping family close.
One team, one contract, from the first measurement to the final walkthrough. Here is exactly how a Portland ADU moves from idea to finished, rentable home.
We start with an in-depth conversation about your goals, whether income, family, or both, and your budget, then visit your Portland home to assess the lot and zoning. This complimentary consult covers ADU feasibility, type options, setbacks, and realistic investment ranges.
Our in-house design team builds detailed plans and 3D renderings for your detached, attached, or conversion ADU, and refines the design with your feedback. We plan the unit to meet Portland’s ADU code as a fully independent, rentable dwelling.
We guide you through durable, efficient finishes and fixtures that hold up in a rental or family unit, drawing on established relationships with premium Portland suppliers. Showroom visits let you see and test selections.
We handle Portland’s ADU zoning review and permitting, then prepare the site. For a detached unit that means foundation work; for a conversion it means opening up and reinforcing the existing structure, with utilities planned in.
We frame and build the unit, then licensed plumbers and electricians install the kitchen, bath, and separate utility connections that make it an independent dwelling. Every City of Portland inspection is coordinated through each phase.
Insulation, drywall, flooring, cabinetry, fixtures, lighting, trim, and paint are completed to a standard that makes the ADU comfortable and rent-ready. The kitchen and bath are dialed in until the unit lives like a real home.
We walk the finished ADU with you, demonstrate how everything works, and hand over maintenance guidance and warranty documentation. The project is not complete until you are fully satisfied, and our 1-year craftsmanship warranty carries on from there.
A look at the detached backyard cottages and attached accessory dwelling units we build across Portland.
Walk through every line that shapes the number, from foundation and systems to kitchen, bath, and finishes, with a calculator built on real Portland ADU project data.
Engaging with Woodland for our home extension was a great decision. They were attentive to our vision, offered valuable insights, and completed the project on time. Their commitment to quality and craftsmanship is truly impressive.
A huge thank you to Woodland Construction Group for the beautiful job they did on our home extension. High-quality craftsmanship throughout.
Woodland Construction Group is an expert in their field. We are very satisfied with their work.
Timelines, cost, Portland zoning, rental income, and what to expect in 2026. If your question is not here, call us. We would rather answer it directly.
A typical Portland ADU takes 4 to 8 months from groundbreaking to final walkthrough, depending on type. A garage or basement conversion can finish in 3 to 5 months, while a new detached backyard unit with its own foundation runs 6 to 9 months once design and Bureau of Development Services permitting are factored in. We set a detailed timeline during design and hold to it.
In Portland, ADUs run $120,000 to $350,000+ in 2026 depending on type, size, and finish level. As a rule of thumb, expect $150 to $400 per square foot, with new detached backyard units at the higher end and garage or basement conversions typically lower since the structure already exists. You get an itemized estimate during the consultation phase so you can see exactly where the budget goes.
Portland is one of the most ADU-friendly cities in the country, allowing accessory dwelling units, and in many cases more than one, on most residential lots, subject to size limits, setbacks, height, and tree rules that vary by zone. Detached, attached, and conversion ADUs each have their own requirements. We assess your lot during the consultation and handle all Bureau of Development Services zoning review, permitting, and inspections.
Yes. A legal ADU can be rented as a long-term unit, which generates steady income in Portland’s tight rental market and helps offset the build cost over time. Many Portland homeowners build an ADU specifically as a rental, or to house family now and rent later. We design the unit to meet city code as a fully independent dwelling so it is rentable and adds lasting value to your property.
We build new detached ADUs (standalone backyard cottages), attached ADUs connected to the main house, garage conversions, and basement conversions, all common across Portland. Each is a fully independent dwelling with its own kitchen, bathroom, and entrance. We help you choose the type that best fits your lot, budget, and goals, whether that is rental income, multigenerational living, or a home office.
Yes. A well-built ADU adds significant resale value and creates an income-producing asset, a strong combination in Portland’s expensive, ADU-friendly housing market. It also adds flexibility: the same unit can house aging parents, adult children, guests, or tenants over the years. That mix of income, flexibility, and added value is why ADUs are one of the highest-return projects in the city.
Yes. An ADU turns underused yard, garage, or basement space into an independent dwelling that can generate rental income, house family, and raise your property value, all on land you already own. With Portland’s nation-leading ADU zoning and strong rental demand, building one is one of the smartest long-term investments a Portland homeowner can make in 2026.
Built for Portland
Portland helped write the playbook for backyard cottages. The city allows accessory dwelling units on most residential lots, has historically waived system development charges, and through its Residential Infill Project made it easier to add a second, and even a third, unit to a single lot. That is why detached ADUs, garage conversions, and basement conversions are everywhere in the inner east and west side, from Alberta Arts and Cully to Sellwood and Multnomah Village. The opportunity is real, but so are the size, setback, height, and tree rules, which is where an experienced builder earns the fee.
Every Portland ADU runs through the City of Portland Bureau of Development Services for zoning review, permitting, and inspections, and the details, lot coverage, height, setbacks, and where the entrance can face, vary by zone. We assess your lot up front, tell you honestly whether a detached unit, a garage conversion, or a basement ADU pencils best, and manage the entire approval process so the unit is legal, rentable, and built to last.
Family-owned and based in Northwest Portland, we build ADUs across the city and the west-side suburbs.
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Book a free in-home consultation. We will assess your lot and zoning, talk through ADU type, layout, and budget, and give you an itemized estimate, with no pressure and no handoffs.
