Lamont Bros.
Portland, OR
4.8(8)
ADU ConstructionDesign-Build ADUHome Addition
Specializing in ADU construction and related services in Portland, OR.
Looking for the best ADU design-build firms in Portland, Oregon? Our directory features 6 vetted adu design-build firms serving the Portland area. Whether you're planning a new ADU construction, garage conversion, or backyard cottage, find the right builder for your project.
Specializing in ADU construction and related services in Portland, OR.
Since 1997, we have built 250+ ADUs in the Portland Metro area for people who want to age in place, keep family close, earn rental income, have a: guest house, home office, entertainment space, studio, home gym...
Specializing in ADU construction and related services in Portland, OR.
Specializing in ADU construction and related services in Portland, OR.
Specializing in ADU construction and related services in Portland, OR.
Specializing in ADU construction and related services in Portland, OR.
Portland is one of the top markets for accessory dwelling units in Oregon. With growing demand for affordable housing, ADU construction in Portland offers homeowners an excellent opportunity to add living space, generate rental income, or house family members. Our curated list of adu design-build firms in Portland helps you find experienced professionals who understand local building codes, zoning regulations, and permit requirements.
ADU construction costs in Portland typically range from $150,000 to $350,000 depending on size, design, and finishes. Garage conversions are generally less expensive ($80,000–$150,000), while custom-built detached ADUs can cost more. Get free quotes from our listed adu design-build firms to compare prices.
Yes, ADU construction in Portland requires building permits. Oregon has specific ADU regulations, and local zoning laws may have additional requirements. Our listed builders can help you navigate the permitting process.
ADU construction timelines in Portland typically range from 4–12 months, depending on the project type. Prefab ADUs can be installed in 2–4 months, while custom builds may take 8–12 months including design and permitting.