Modern DADU in Seattle
Meadowbrook Neighborhood
A compact 400 sq ft one-bedroom DADU on an NR2 lot in Seattle's Meadowbrook neighborhood. Open-concept living with integrated kitchen, full bathroom, and a skylight for natural overhead light. Ceiling heights range from 10' to 12', making the small footprint feel spacious. All seven existing trees on the property are preserved. Built by Evercrest LLC, a licensed general contractor specializing in detached ADU (DADU) and backyard cottage construction across the Greater Seattle area.
Elevations
All four views — South, East, North, West — show a clean single-story structure with a shed-style roofline reaching 13'-2" at the peak.
Hardie plank cement board siding with continuous gutters and downspouts. Egress windows on the bedroom side, generous glazing on the south-facing wall for natural light.
Average grade sits at 4.5' below main floor level, providing good drainage and foundation clearance.
Cross Section
Roof layers: Class A asphalt shingles, 15 lb roofing paper, 1/2" sheathing, rafters @24" OC, R-38 fiberglass batt insulation, 1/2" drywall.
Wall layers: Hardie plank cement board, water-resistive barrier, R-5 continuous insulation, 3/8" plywood, R-20 fiberglass batt, 2x6 stud, Class I vapor retarder, 1/2" drywall.
Floor layers: Carpet, 5/8" plywood, R-10 rigid insulation, 10 mil vapor barrier, concrete slab on grade.
Roof Plan & Ventilation
Pre-fab wood truss roof construction. Roof area: 400 sq ft with a 25' × 25' footprint plus 1'-6" eave overhangs on all sides.
Ventilation: 4" Ezvent – 5/16" Ezvent eave ventilation system. 21 linear feet of eave ventilation provides 394 sq in — exceeding the required 384 sq in minimum.
Two V12 H3 skylights centered on the ridge line for natural daylighting.
Building Specifications
Permit
Approved: October 20, 2025
Authority: City of Seattle SDCI
Codes: 2021 IRC, WSEC 2021, SMC
Project Team
General Contractor: Evercrest LLC
Architect: Global Precision Designs Inc.
Engineer: PE licensed in WA
Understanding DADUs in Seattle
A DADU (Detached Accessory Dwelling Unit), also known as a backyard cottage, is a standalone structure built separately from the main home on the same lot. Seattle allows one DADU on most single-family lots under current zoning rules, with a maximum footprint of 1,000 sq ft. DADUs offer maximum privacy for rental income or multigenerational living — they share the lot but not the walls. The City of Seattle's SDCI department processes DADU permits, and Evercrest LLC handles the entire process from design through final inspection.
Detached ADU (DADU) Construction in Seattle — FAQ
Detached ADU (DADU) construction costs in Seattle typically range from $250 to $400+ per square foot depending on finishes, site conditions, and foundation requirements. A 400 sq ft DADU like this Meadowbrook project generally falls in the $150,000–$200,000 range. Evercrest LLC provides fixed-price contracts so your budget is locked in before construction begins.
Seattle SDCI currently processes detached ADU (DADU) permits in 4–8 months depending on backlog and plan complexity. Evercrest LLC handles all permit submissions, plan revisions, and inspector communication.
Seattle allows detached ADUs (DADUs), also called backyard cottages, up to 1,000 sq ft of living space on single-family lots. The actual buildable size depends on lot coverage limits, setback requirements, and rear yard restrictions specific to your lot's zoning.
Yes. Seattle allows DADUs to be rented as long-term rentals with no owner-occupancy requirement since 2019. Meadowbrook is a desirable NE Seattle neighborhood close to Lake City, Nathan Hale High School, and Meadowbrook Community Center.
Seattle detached ADUs (DADUs) must connect to the city sewer system. Side sewer connections are a standard part of the permitting process. Evercrest LLC coordinates all utility connections as part of our full-service construction.
Any Seattle single-family zone (NR1, NR2, NR3) allows detached ADUs (backyard cottages). Popular neighborhoods include Meadowbrook, Ballard, Wallingford, Greenwood, Columbia City, Beacon Hill, and West Seattle.
Ready to Build Your Backyard Cottage in Seattle?
Evercrest LLC handles design, permits, and construction — one team, one contract, one point of contact.
Get a Free Feasibility Check
