KEYSTONE CONSTRUCTION
Attached & Detached (DADU) builder · Seattle, King County
WA L&I registration: unknown (as of May 2026)1 ADUs permitted
in Seattle / King County · verified from public permit records
Verified permits
1
Permitting since
2011
Service area
King County
ADU types
AttachedDetached (DADU)
Verified permit record
1 ADU building permits on public record in King County, 2011 — 1 detached, 1 attached. Drawn from City of Seattle permit data and matched to KEYSTONE CONSTRUCTION's Washington contractor registration. Project addresses are not published.
Project photos
Project photos appear once KEYSTONE CONSTRUCTION claims this listing.
About
No description added yet.
Permit record: City of Seattle SDCI permit data.
License status: WA L&I (data.wa.gov).