Basements, additions & ADUs
Add living space, rental income or room for family with a finished basement, an addition or a backyard ADU, built from framing to finish.
What we build
- Basement finishing
- ADUs and backyard cottages (DADUs)
- Garage conversions
- Home additions
- Framing and structural carpentry
- Drywall, trim, flooring and paint
Why add an ADU?
Washington has made it easier to add accessory dwelling units, and homeowners around Seattle and Snohomish County are building them for rental income, aging parents or grown kids who need a place of their own.
An ADU can be a converted basement or garage (an attached ADU) or a separate backyard cottage (a detached ADU, or DADU). Rules on size, parking and setbacks vary from city to city, so at the first visit we'll go over what's possible on your lot.
Finishing a basement
An unfinished basement is often the most affordable square footage you can add. We frame, insulate, drywall and finish it into a family room, bedroom, office or rental unit, then add the flooring, trim and paint so it feels like part of the house.
Before & after
Basement & ADU questions
Do I need a permit?
Most basement finishes, additions and ADUs need permits. We'll talk through permits and plans with you at the first visit.
How much does an ADU cost?
It depends on the size, the site and the finishes you choose. After visiting, we'll give you a written estimate so you can plan with real numbers.
Can my basement become a rental unit?
Often, yes, as an attached ADU, as long as the space can meet code requirements like ceiling height and emergency exits (egress windows). We'll look at your space and tell you what it would take.
Areas we serve
We work across Seattle, Shoreline, Lake Forest Park, Edmonds, Lynnwood, Mountlake Terrace, Mill Creek, Mukilteo, Everett, Marysville, Bothell, Kenmore, Woodinville and Snohomish. See all service areas
Other services
Ready to get started?
Tell us about your project and get a free, written estimate. Or see a ballpark price in our 3D planner.