Skip to main content Skip to content Detached ADUs, attached units, garage conversions, and basement ADUs. Woodland Construction Group designs and builds Bethany accessory dwelling units that meet Washington County code and pay you back, one accountable team from first sketch to final walkthrough.
Review the Washington County ADU permitting requirements before you begin.Planning an ADU in Bethany, Oregon? An accessory dwelling unit is a complete, independent living space: kitchen, bath, sleeping area, and its own entrance. It is one of the smartest ways to add rental income or house family without leaving your lot.
Bethany sits in unincorporated Washington County, so ADU rules, siting, and utility requirements follow county code, which differs from the City of Portland. Getting that right from the start is what keeps a project on schedule.
We handle siting, utilities, permitting, and construction as one design-build project, so your Bethany ADU is buildable, code-correct, and finished to last.
ADUs in the Bethany area typically run $150,000 to $400,000. A detached ADU usually lands between $200,000 and $400,000, or roughly $300 to $500 per square foot, while garage and basement conversions can cost less.
An ADU can generate ongoing rental income, house multigenerational family, and add lasting value to your Bethany property, all on land you already own.
Design-build experience across the Portland metro
Homes transformed in Bethany and the west side
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Craftsmanship warranty on every project
An ADU does three things at once for Bethany homeowners: it creates rental income, it gives aging parents or adult children a private place to live, and it adds long-term value to your property.
Because Bethany is unincorporated Washington County, ADU siting, size limits, parking, and utility connections follow county rules. We confirm what your specific parcel allows before design, so the plan does not stall at permitting.
From a detached cottage in the backyard to a garage or basement conversion, we build ADUs as complete, independent homes, designed to attract good tenants or welcome family.
Woodland Construction Group · 18 Years Experience · Serving Bethany & Washington County
We design and build detached and attached ADUs across Bethany and the Portland metro, handling siting, utilities, and Washington County code under one design-build contract from concept to certificate of occupancy.
A well-built ADU in Bethany can generate steady rental income while adding property value, turning unused yard, garage, or basement space into a second income-producing home.
We build every kind of ADU in Bethany. Each one is a complete, independent home, designed for income, family, or both.
A freestanding cottage in the backyard with its own kitchen, bath, and entrance, designed for privacy and rental appeal.
A unit built onto or carved from the main home, with a separate entrance and full independence from the primary residence.
Turning an existing garage into a code-correct living unit, often the most cost-effective path to a Bethany ADU.
A self-contained lower-level unit with egress, a kitchenette, and a bath, using square footage you already have.
Layouts, finishes, and durability chosen to attract good tenants and stand up to years of rental use.
Water, sewer, and electrical connections plus parking and placement, planned to meet Washington County requirements.
How We Work
One team, one contract, from the first measurement to the final walkthrough, with no handoffs between designer, builder, and trades: design and 3D layouts, material selection, permitting and inspections, careful demolition, licensed construction, and a final walkthrough, all backed by our 1-year craftsmanship warranty.
See our full design-build processDetached accessory dwelling units built as complete, independent homes for income and family.
See how detached versus conversion, size, and utility connections each shape the number, with a calculator built on real Portland-metro ADU 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, permits, cost, and what to expect in 2026. If your question is not here, call us. We would rather answer it directly.
A detached ADU in Bethany typically takes 5 to 9 months including design, Washington County permitting, and construction. Garage and basement conversions can be faster. We give you a realistic schedule once siting and permits are confirmed.
ADUs in Bethany run $150,000 to $400,000. A detached unit usually lands between $200,000 and $400,000, or about $300 to $500 per square foot. Garage and basement conversions often cost less because the shell already exists. You get an itemized estimate during the consultation.
Because Bethany is unincorporated Washington County, ADUs follow county code, not City of Portland rules. Size limits, setbacks, parking, and utility connections are set by the county and vary by parcel. We confirm exactly what your lot allows before design begins.
Yes. ADUs are commonly built for rental income in the Bethany area. We design layouts, finishes, and durability to attract good long-term tenants and stand up to rental use, while meeting all Washington County requirements.
We build detached cottages, attached units, garage conversions, and basement ADUs. The right type depends on your lot, budget, and goals. Garage and basement conversions are often the most cost-effective, while a detached ADU offers the most privacy and rental appeal.
For many homeowners, yes. An ADU can produce ongoing rental income, house family affordably, and add lasting value to your property, all on land you already own. We are happy to walk through the numbers for your specific lot.
Family-owned and based in Northwest Portland, we design and build across Bethany, North Bethany, and the surrounding Washington County communities.
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Book a free in-home consultation. We will review your lot, confirm Washington County ADU rules, talk through design and budget, and give you a buildable, itemized plan, with no pressure and no handoffs.
