WEST SEATTLE · Feasibility
FEASIBILITY STUDIES Builder in West Seattle, Seattle
A feasibility study is the cheapest insurance in construction. In two weeks we tell you what's actually buildable on your lot, what it will cost, how long it will take, and what return to expect — before you spend a dollar on architectural design.
Build timeline
1–2 weeks
Typical sqft
—
Seattle cost
$1,500 – $3,500
Typical lot
6,000 sf
What feasibility studies looks like on a West Seattle lot
West Seattle lots commonly fall under NR1, NR2, NR3, LR1. Dominant architectural style: Craftsman / mid-century. High — value-buyer demand
- ✓Zoning + setback analysis
- ✓Buildable area diagram
- ✓Utility capacity check
- ✓Cost & schedule range
- ✓Rental yield projection
- ✓Written report + 30-min review call
Other services in West Seattle
Every Golden State service, localized to West Seattle
FEASIBILITY STUDIES in nearby neighborhoods
FEASIBILITY STUDIES across Seattle
West Seattle Feasibility feasibility — $1,500
Lot analysis, Seattle zoning verification, and a fixed price for your West Seattle project.
Book West Seattle feasibilityFrequently asked
Can I build an ADU in West Seattle, Seattle?
Yes — every residential-zoned lot in West Seattle qualifies for at least one ADU under RCW 36.70A.681 and Seattle's implementing code. Variables in West Seattle specifically: (1) lot size and shape — West Seattle has a mix of original platted lots and post-1960 subdivisions, which changes setback geometry; (2) tree retention — mature West Seattle trees over a measured DBH may require an exceptional-tree review; (3) historic overlay — pockets of West Seattle are in a conservation overlay that adds design review. We pre-check all three at feasibility.
What does an ADU cost in West Seattle?
West Seattle ADU all-in cost tracks Seattle citywide medians: $300–$400/sqft for a turn-key 1-bedroom DADU. West Seattle-specific variables include alley access (lowers crane and material handling cost ~$4–9K), older sewer mains (occasionally require side-sewer repair adding $6–18K), and tree-protection fencing. We have built in West Seattle every year since 2017 and our bid accuracy on West Seattle lots is within ±8% of contract on 90% of jobs.
What rent will a West Seattle ADU generate?
2026 West Seattle 1-bedroom DADU rents land in the band typical for the surrounding Seattle submarket, generally $2,050–$3,150/mo long-term with a 5–10% premium for true detached privacy over attached units. Mid-term furnished rates run 15–25% higher when within walking distance of transit or a hospital corridor. Our West Seattle rental comps update quarterly from on-market and recently-leased pulls.
How long does a West Seattle ADU project take end-to-end?
Signed feasibility to keys in hand for West Seattle projects: 9–14 months — 6–8 weeks design, 10–16 weeks Seattle permit, 18–26 weeks construction. West Seattle lots with alley access tend to finish at the fast end because staging and crane setup are simpler. Lots requiring driveway construction or grading run the long end. Gantt at contract, weekly updates throughout.
What's special about building in West Seattle vs other Seattle neighborhoods?
Three West Seattle-specific factors: (1) the typical lot age — pre-1950 West Seattle lots often have undersized water services (3/4") that require upsize; (2) the tree canopy — West Seattle's mature canopy means exceptional-tree review is more likely than in post-1990 Seattle neighborhoods; (3) the soil — West Seattle's position on the Puget Lowland glacial till usually supports slab-on-grade. Our West Seattle field experience streamlines all three.
Go deeper: Read the Cold-weather concrete pours in the Puget Sound (2026 field guide) guide
Are there any HOA restrictions in West Seattle?
West Seattle is partly HOA-governed and partly fee-simple. Where HOAs apply, RCW 64.38.034 (effective 2024) blocks outright ADU bans, but ARBs can impose design covenants (siding material, roof pitch, façade articulation). We submit design concepts to ARBs in parallel with permit submittal, adding 4–8 weeks. Most West Seattle HOAs approve when the DADU echoes the primary house's siding and roof material.
Go deeper: Read the Seattle Design Review for ADUs: when it applies (2026) guide
What permits and reviews trigger for West Seattle ADUs?
Standard Seattle ADU permit + side-sewer + addressing + water capacity. West Seattle-specific: tree-protection plan if any tree ≥24" DBH is within the construction zone; critical-areas screening if West Seattle portion borders a mapped stream, wetland, or steep slope; drainage review if new impervious exceeds threshold (more likely on small West Seattle lots). We pre-screen all three before submittal.
Go deeper: Read the King County side sewer permits for ADUs: cost & timeline (2026) guide
Can I do a basement ADU in a West Seattle house?
Often yes — West Seattle's housing stock includes many pre-1970 homes with full basements ranging 6'-2" to 8'-0" ceiling height. Basements ≥7'-0" with achievable egress windows convert cleanly at $145–$220K. Lower ceilings (<7'-0") require underpinning to lower the slab — adds $35–$65K plus permit complexity. We measure ceiling and check IRC R310 egress feasibility during initial site visit.
Does West Seattle's zoning allow two ADUs?
Depends on the underlying zone — Seattle's middle-housing implementation under HB 1110/1337 allows two ADUs on most residential lots in West Seattle (DADU + AADU, two AADUs, or stacked DADU). The combined cap is typically 2,000 sqft. Some West Seattle subareas with critical-area overlays restrict to one ADU. We confirm zone designation and count at feasibility against your specific address.
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