1903 S 128th St, Seatac, WA 98168

Office · Seatac · Seattle-Bellevue metro, WA

One of 37 reachable office buildings in Seatac. Larger than 81% of office buildings in Seatac (median 14,270 SF), derived from assessor records.

Usable building area
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
Medical/Dental Office, King County Assessor
Assessed value
$16,989,000, per the King County Assessor (not a market appraisal)
Assessed value per usable SF
$260.98/SF, derived from assessor records
Usable area / lot
0.38, 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: $17.9M (estimated market value), with a likely range of $15.8M to $23M (half of recent verified sales in this segment landed inside that range). Based on 4 verified arm's-length comparable sales (through 2026-06-01). Not an appraisal. How this estimate works.

lower confidence: 0 comparable sales within 3 miles; nearest 8.4 mi. This property type carries wider measured error; treat the estimate as a starting point. Comparable-sale caveat: the estimate is 58% above the $173.25/SF median of the shown comparable sales.

Comparable sales used as evidence

Recorded arm's-length sales of similar buildings nearby; nearer and more recent sales rank first. Buyer and seller names are withheld. Get this data via API.

Ownership tenure is not asserted for this parcel: the most recent recorded transfer is a non-market conveyance.

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

Value over time

$0$10M$20M$30M201120142017202020232026$17.9M$17MCounty assessed valueMakeMe Estimate range

Dark line: county assessed value per King County tax rolls. Blue line: our estimate; dashed years are a modeled backcast built from recorded arm's-length sales in the building's segment, not estimates published at the time, and years without enough sales stay unmodeled. The shaded range is the model's measured error band; about half of verified sales in the segment land inside it. 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).