850 Republican St, Seattle, WA 98109

Office · Seattle · Seattle-Bellevue metro, WA

Imagery suggests: office building, 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 AI estimate from public imagery; may be outdated.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 76% of office buildings in Seattle (median 20,410 SF), derived from assessor records.

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Building size: 102,235 SF, King County Assessor
Lot size: 33,696 SF, King County Assessor
Year built: 1963, King County Assessor
Stories: 4, King County Assessor
Predominant use: Research Laboratories, King County Assessor
Assessed value: $83,796,000, per the King County Assessor (not a market appraisal)
Assessed value per building SF: $819.64/SF, derived from assessor records
Lot coverage: 303%, derived from assessor records
Vintage: 1960s vintage
Zoning: SM-SLU 175/85-280, King County
County use code: Medical/Dental Office
Construction (observed): masonry, 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.

850 Republican St, Seattle · 0 mi · 436,497 SF · built 2008 · assessed $577.43/SF
901 Mercer St, Seattle · 0.1 mi · 593,200 SF · built 2013 · assessed $144.66/SF
750 Republican St, Seattle · 0.1 mi · 339,591 SF · built 2013 · assessed $530.52/SF
601 Westlake Ave N, Seattle · 0.1 mi · 356,410 SF · built 2015 · assessed $545.41/SF
750 Republican St, Seattle · 0.1 mi · 164,220 SF · built 2018 · assessed $801.12/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: $78,308,227 (estimated market value), with a likely range of $70,771,227 to $102,031,914 (half of recent verified sales in this segment landed inside that range). Based on 55 verified arm's-length comparable sales (through 2026-05-29). Not an appraisal. How this estimate works.

Last sold: 2016-08-31 for $34,736,000 (recorded arm's-length sale).

Current ownership dates to 2016 (about 10 years) per recorded transfers.

2 administrative transfers (no consideration), 2016 to 2017

2016-08-31: $34,736,000 from City Investors XII LLC to Terra Funding-Bio Med LLC, rec. 20160831002576

2009-09-04: transfer from City Investors XII LLC to Seattle City of (non-market transfer), rec. 20090910001140

2000-12-22: $25,000,000 from Puget Western INC to City Investors XII LLC, rec. 20010102000536

2000-10-28: transfer from Puget Sound Energy INC to Puget Western INC (non-market transfer), rec. 20001103000946

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 $33,179,900 (2011) to $83,796,000 (2026), up 153% over 15 years, per county tax rolls. The 2026 roll splits $83,796,000 into $32,011,200 land and $51,784,800 improvements.

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

Lot: 33,696 sq ft

Water: Water District (per King County)

Sewer: Public (per King County)

Access: Public

Street surface: Paved

Floor and use mix: Laboratories 102,235 SF (county building sections)

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

Permit history

2015-05-12: Remodel, declared value $191,354 (Screened), permit 6473637

2012-08-08: Remodel, declared value $870,000 (Complete), permit 6305042

2012-07-23: Remodel, declared value $100,500 (Complete), permit 6312751

2012-07-16: Remodel, declared value $430,000 (Complete), permit 6318772

2009-02-06: Remodel, declared value $256,000 (Complete), permit 6205207

2007-02-02: Building, New, declared value $27,400,307 (Complete), permit 6091904

2006-10-25: Building, New, declared value $14,000,000 (Complete), permit 6115244

2006-07-28: Building, New, declared value $13,200,000 (Complete), permit 6082388

2006-05-19: Other, declared value $4,000,000 (Complete), permit 6074186

2006-05-05: Demolition (Complete), permit 6082385

Source: King County permit records (newest first).