1903 S 128th St, Seatac, WA 98168

Office · Seatac · Seattle-Bellevue metro, WA

One of 34 reachable office buildings in Seatac. Larger than 79% of office buildings in Seatac (median 20,852 SF), derived from assessor records.

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Building size
65,098 SF, King County Assessor
Lot size
172,349 SF, King County Assessor
Year built
2019, King County Assessor
Stories
2, King County Assessor
Buildings on parcel
2, King County Assessor
Predominant use
Support Services Pavilion, King County Assessor
Assessed value
$16,989,000, per the King County Assessor (not a market appraisal)
Assessed value per building SF
$260.98/SF, derived from assessor records
Lot coverage
38%, derived from assessor records
Vintage
2010s vintage
Zoning
RBX, King County
County use code
Medical/Dental Office

Nearby comparable buildings

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

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Sale history and market context

MakeMe Estimate: $19,549,739 (estimated market value), with a likely range of $17,668,118 to $25,472,385 (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.

Current ownership dates to 2017 (about 9 years) per recorded transfers.

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

Value over time

$7.49M$15M$22.5M$30M201120142017202020232026County appraised valueEstimated value (modeled range)

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 $1,034,000 (2011) to $16,989,000 (2026), up 1543% over 15 years, per county tax rolls. The 2026 roll splits $16,989,000 into $3,446,900 land and $13,542,100 improvements.

Taxes

Permit history

Source: King County permit records (newest first).