Skip to main content Skip to content Detached ADUs, garage conversions, and in-law suites built to City of Hillsboro code. Woodland Construction Group designs and builds accessory dwelling units for rental income and family across Hillsboro, one accountable team from zoning to keys.
Review the City of Hillsboro ADU permitting requirements before you begin.Planning an ADU in Hillsboro, Oregon? An accessory dwelling unit is a small, complete home: its own kitchen, bath, living space, and entrance, on the lot you already own. It is also a full ground-up build with foundation, framing, utilities, and finish, governed by specific City of Hillsboro and state ADU rules.
Done right, an ADU generates rental income, houses aging parents or adult kids, or gives you a flexible work-from-home or guest space, all while adding lasting value to your property in a tight Hillsboro market.
The right partner navigates zoning, setbacks, and utility connections, designs an ADU that fits the lot and the main house, and delivers a turnkey second home that meets every code requirement.
A detached ADU in Hillsboro typically runs $150,000 to $350,000+, depending on size, site work, and finish, while garage conversions and attached ADUs can come in lower because some structure already exists.
Oregon and City of Hillsboro rules now make ADUs easier to permit than in the past, and a well-built unit can produce steady rental income or provide multigenerational housing while increasing overall property value.
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An ADU turns unused yard or garage into a second income stream or a private home for family, on land you already own. In Hillsboro’s tight rental market, a legal unit can meaningfully offset a mortgage.
It is also flexibility you keep for decades. The same unit can house a college kid, then aging parents, then a renter, then a home office, adapting as your needs change without another move or another mortgage.
Because Oregon and Hillsboro have streamlined ADU rules, a well-designed unit is more attainable than many homeowners expect, and it adds durable value to the property while easing the region’s housing crunch.
Woodland Construction Group · 18 Years Experience · Serving Hillsboro, Oregon
Our licensed team designs and builds detached ADUs, garage conversions, and attached units across Hillsboro and Washington County, handling zoning, setbacks, utilities, and finish to City of Hillsboro and Oregon code.
Oregon and City of Hillsboro rules have made ADUs easier to permit, and a well-built unit can generate steady rental income or house multigenerational family on the lot you already own.
Lot type drives the ADU strategy in Hillsboro. Larger mid-century lots near Reedville and Jackson School often have room for a true detached ADU with its own entrance and yard, while existing detached garages across the city are strong candidates for conversion into a unit at lower cost.
In Orenco Station and the newer South Hillsboro communities, lot coverage and setbacks are tighter, so attached or compact detached units, and lower-level suites, are often the better fit. We evaluate zoning, utilities, and access before recommending a type.
ADUs are permitted under City of Hillsboro and Oregon ADU standards, covering size limits, setbacks, parking, and utility connections, with building, electrical, plumbing, and mechanical permits through the Hillsboro Permitting Center. We manage zoning review, permits, and inspections end to end.
Five ADU types cover most Hillsboro lots, plus the finish quality that makes a unit a real home. Each is designed to fit the property and meet City of Hillsboro and Oregon code.
A standalone second home with its own foundation, entrance, kitchen, and bath, sized and placed to fit the lot and complement the main house.
Turning an existing detached or attached garage into a legal dwelling, often the most cost-effective ADU because the shell already exists.
A unit built onto or within the main home with a private entrance, ideal for tighter Orenco and South Hillsboro lots.
Rentable ADUs designed for durability, privacy, and separate utilities, built to generate steady income in Hillsboro’s rental market.
In-law and family suites that keep parents or adult children close with their own space, accessibility options, and independence.
Full kitchens, baths, flooring, and systems finished to the same standard as the main home, so the ADU lives like a real residence.
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 processA look at detached units, conversions, and suites we build as complete second homes across Hillsboro and the west-side metro.
Walk through how detached versus conversion, size, site work, and finish shape the number, with guidance built on real Portland-area 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 Hillsboro typically takes 5 to 9 months from design through final inspection, including permitting. Garage conversions can be faster because the shell exists. We build a schedule during design that accounts for the City of Hillsboro review timeline.
A detached ADU in Hillsboro generally runs $150,000 to $350,000+, depending on size, site work, and finish. Garage conversions and attached units can cost less because some structure already exists. You get an itemized estimate after the design and site assessment.
ADUs follow City of Hillsboro and Oregon standards covering size limits, setbacks, height, parking, and utility connections. Oregon has streamlined ADU rules in recent years. We confirm what your specific lot allows during the zoning review at the start of design.
Often, yes. An existing detached or attached garage is frequently the most cost-effective path to a legal ADU because the foundation and shell are already there. We assess the structure, utilities, and zoning to confirm feasibility.
Yes, where zoning allows. A legal ADU built to code can be rented for income, and many Hillsboro homeowners use one to offset their mortgage in a tight rental market. We design units with the durability, privacy, and separate utilities that rentals need.
It depends on the design and the unit type. Some ADUs share connections with the main home while others get separate meters, which is often preferred for rentals. We plan utility connections during design and coordinate them with the City of Hillsboro.
For many homeowners, yes. An ADU can generate steady rental income, house multigenerational family, and add lasting value to your property, all on land you already own, which is compelling in Hillsboro’s tight housing market.
Family-owned and based in Northwest Portland, we design and build ADUs across Hillsboro and the surrounding Washington County communities.
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Book a free site consultation. We will review zoning, lot fit, and utilities, talk through budget, and give you an itemized plan with no pressure and no handoffs.
