320 Westlake Ave N, Seattle, WA 98109

Office · Seattle · Seattle-Bellevue metro, WA

Imagery suggests: mid-rise mixed-use, appears multi-tenant. AI estimate from public imagery. In recent public imagery (2026-06), the building appears well maintained. AI estimate from public imagery; may be outdated.

One of 957 reachable office buildings in Seattle. Larger than 89% of office buildings in Seattle (median 20,410 SF), derived from assessor records.

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Building size: 303,103 SF, King County Assessor
Lot size: 38,880 SF, King County Assessor
Year built: 2006, King County Assessor
Stories: 6, King County Assessor
Predominant use: West Blk - Westlake/Terry Bldg., King County Assessor
Assessed value: $75,115,000, per the King County Assessor (not a market appraisal)
Assessed value per building SF: $247.82/SF, derived from assessor records
Lot coverage: 780%, derived from assessor records
Vintage: 2000s vintage
Zoning: SM-SLU 175/85-280, King County
County use code: Office Building
Construction (observed): steel glass, AI estimate from public imagery
Parking (observed): street only, AI estimate from public imagery
Frontage (observed): mid block, AI estimate from public imagery

Nearby comparable buildings

Same building type, by distance. Assessor facts only; not an opinion of value.

307 Westlake Ave N, Seattle · 0 mi · 162,200 SF · built 2003 · assessed $451.08/SF
321 Terry Ave N, Seattle · 0 mi · 209,816 SF · built 2006 · assessed $259.18/SF
400 Westlake Ave N, Seattle · 0.1 mi · 268,005 SF · built 2022 · assessed $234.80/SF
224 Westlake Ave N, Seattle · 0.1 mi · 36,513 SF · built 1926 · assessed $294.42/SF
225 Terry Ave N, Seattle · 0.1 mi · 69,040 SF · built 2007 · assessed $164.50/SF
903 Thomas St, Seattle · 0.1 mi · 254,218 SF · built 2018 · assessed $202.92/SF

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Sale history and market context

MakeMe Estimate: $66,161,076 (estimated market value), with a likely range of $59,793,214 to $86,204,751 (half of recent verified sales in this segment landed inside that range). Based on 12 verified arm's-length comparable sales (through 2026-05-29). Not an appraisal. How this estimate works.

Current ownership dates to 2013 (about 13 years) per recorded transfers.

2013-01-16: $169,950,000 from Westlake Terry Venture LLC to KR Westlake Terry LLC (part of a 2-parcel sale; price is the whole deal), rec. 20130116001522

2006-06-16: transfer from Westlake Terry Venture LLC to Seattle City of (part of a 5-parcel sale; price is the whole deal), rec. 20060616002432

2006-02-08: $3,857,250 from City Investors V LLC to Westlake Terry LLC (part of a 3-parcel sale; price is the whole deal), rec. 20060209002360

1996-06-19: transfer from Private party to City Investors V LLC /Vulcan NW INC (part of a 2-parcel sale; price is the whole deal), rec. 199606201467

1992-10-09: $1,675,000 from Old Frontier Land CO to Private party (part of a 2-parcel sale; price is the whole deal), rec. 199210090647

Source: King County recorded sales extract; buyer and seller shown only when a company or organization. Individual names are withheld.

Value over time

Solid line: county appraised value per King County tax rolls. Shaded range: our modeled estimate for each year, built from recorded arm's-length sales in the building's segment; years without enough sales stay unmodeled. Dots: recorded arm's-length sales. Not an appraisal. How this estimate works.

Land, site, and value history

Assessed value moved from $51,149,000 (2011) to $75,115,000 (2026), up 47% over 15 years, per county tax rolls. The 2026 roll splits $75,115,000 into $36,936,000 land and $38,179,000 improvements.

Zoning: SM-SLU 175/85-280 (per King County)

Lot: 38,880 sq ft

Water: Water District (per King County)

Sewer: Public (per King County)

Access: Public

Street surface: Paved

Floor and use mix: Office Building 158,414 SF; Underground Parking Structure 109,905 SF; Retail Store 34,784 SF (county building sections)

County districts report (schools, fire, sewer, council; on kingcounty.gov)

Permit history

2025-11-03: Remodel, declared value $1,360,000, permit 7074272-CN

2025-07-21: Remodel, declared value $30,000, permit 7084719-CN

2025-07-08: Remodel, declared value $220,000, permit 7093334-CN

2025-01-16: Remodel, declared value $77,980 (Screened), permit 7064830-CN

2018-04-27: Remodel, declared value $444,000 (Screened), permit 6636783

2018-01-11: Remodel, declared value $160,000 (Screened), permit 6639419

2017-09-16: Remodel, declared value $2,615,198 (Screened), permit 6578737

2017-06-29: Remodel, declared value $40,000 (Screened), permit 6595852

2014-03-28: Remodel, declared value $100,000 (Screened), permit 6410924

2014-02-24: Remodel, declared value $150,000 (Screened), permit 6402133

Source: King County permit records (newest first).