428 Westlake Ave N, Seattle, WA 98109

Office · Seattle · Seattle-Bellevue metro, WA

Imagery suggests: parking garage. 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 AI estimate from public imagery; may be outdated.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 80% of office buildings in Seattle (median 20,410 SF), derived from assessor records.

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Building size: 144,282 SF, King County Assessor
Lot size: 19,080 SF, King County Assessor
Year built: 2004, King County Assessor
Stories: 6, King County Assessor
Predominant use: 428 Westlake, King County Assessor
Assessed value: $32,971,000, per the King County Assessor (not a market appraisal)
Assessed value per building SF: $228.52/SF, derived from assessor records
Lot coverage: 756%, derived from assessor records
Vintage: 2000s vintage
Zoning: SM-SLU 175/85-280, King County
County use code: Office Building
Construction (observed): metal, AI estimate from public imagery
Parking (observed): structured, AI estimate from public imagery

Nearby comparable buildings

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

401 Terry Ave N, Seattle · 0 mi · 258,505 SF · built 2003 · assessed $281.44/SF
400 Westlake Ave N, Seattle · 0 mi · 268,005 SF · built 2022 · assessed $234.80/SF
960 Republican St, Seattle · 0.1 mi · 60,375 SF · built 1928 · assessed $738.22/SF
440 Terry Ave N, Seattle · 0.1 mi · 508,139 SF · built 2009 · assessed $149.77/SF
400 9th Ave N, Seattle · 0.1 mi · 483,397 SF · built 2014 · assessed $227.53/SF
530 Westlake Ave N, Seattle · 0.1 mi · 512,665 SF · built 2021 · assessed $235.36/SF

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Sale history and market context

MakeMe Estimate: $30,082,775 (estimated market value), with a likely range of $27,187,372 to $39,196,432 (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.

Last sold: 2024-09-20 for $47,600,000 (recorded arm's-length sale).

Current ownership dates to 2024 (about 2 years) per recorded transfers.

2024-09-20: $47,600,000 from Karigo LLC to Are Seattle No 53 LLC, rec. 20241001000717

2019-04-10: transfer from Karigo LLC to Seattle City of (non-market transfer), rec. 20190419000158

2017-06-30: $81,500,000 from City Investors IX LLC to Karigo LLC, rec. 20170630000855

2 administrative transfers (no consideration), 2003 to 2017

1999-11-05: $9,204,000 from P.b Investments LP to Private party (part of a 3-parcel sale; price is the whole deal), rec. 19991109000612

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 $19,096,000 (2011) to $32,971,000 (2026), up 73% over 15 years, per county tax rolls. The 2026 roll splits $32,971,000 into $18,126,000 land and $14,845,000 improvements.

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

Lot: 19,080 sq ft

Water: Water District (per King County)

Sewer: Public (per King County)

Access: Public

Street surface: Paved

Floor and use mix: Office Building 86,700 SF; Basement, Parking 52,582 SF; Retail Store 5,000 SF (county building sections)

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

Permit history

2025-07-08: Remodel, declared value $20,000, permit 7092316-CN

2024-04-08: Remodel, declared value $124,462 (Screened), permit 7009600-CN

2018-08-27: Remodel, declared value $1,000 (Screened), permit 6685573-CN

2018-08-16: Remodel, declared value $150,000 (Screened), permit 6647450-CN

2018-08-06: Remodel, declared value $4,000 (Screened), permit 6682050-CN

2018-08-06: Remodel, declared value $3,000 (Screened), permit 6682058-CN

2017-08-31: Remodel, declared value $150,000 (Screened), permit 6602458

2017-04-03: Remodel, declared value $4,520,000 (Screened), permit 6554865

2017-01-11: Remodel, declared value $3,035,000 (Screened), permit 6567942

2016-03-10: Remodel, declared value $60,000 (Screened), permit 6500401

Source: King County permit records (newest first).