15220 6th Ave SW, Burien, WA 98166

Office · Burien · Seattle-Bellevue metro, WA

One of 141 reachable office buildings in Burien. Larger than 31% of office buildings in Burien (median 3,748 SF), derived from assessor records.

Usable building area
3,080 SF, King County Assessor
Lot size
7,290 SF, King County Assessor
Year built
1955, King County Assessor
Stories
1, King County Assessor
Predominant use
Office, King County Assessor
Assessed value
$741,300, per the King County Assessor (not a market appraisal)
Assessed value per usable SF
$240.68/SF, derived from assessor records
Usable area / lot
0.42, derived from assessor records
Vintage
1950s vintage
Zoning
MU-DT, King County
County use code
Office Building

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: $1M (estimated market value), with a likely range of $886K to $1.16M (half of recent verified sales in this segment landed inside that range). Based on 8 verified arm's-length comparable sales (through 2026-06-01). Not an appraisal. How this estimate works.

lower confidence: 3 comparable sales within 3 miles; nearest 0.1 mi. This property type carries wider measured error; treat the estimate as a starting point. Recent sale check: this building sold for $785,000 in 2024; the estimate is about 28% apart. Treat the recorded trade as strong evidence alongside the model.

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.

Market context: Office in Burien

median verified sale $302.42/SF over the trailing 24 months; 4 sales in the last 12 months and 6 in 24 (newest verified sale 2026-04).

Computed from 144 verified arm's-length sales in King County public records (6 in the trailing 24 months). Free public records. Not an appraisal.

Last sold: 2024-12-17 for $785,000 (recorded arm's-length sale).

Current ownership dates to 2024 (about 2 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

$0$500K$1M$1.5M201120142017202020232026Last sold $785K · 2024$1M$741KCounty assessed valueMakeMe Estimate rangeRecorded sale

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. Diamonds: recorded arm's-length sales. Not an appraisal. How this estimate works.

Land, site, and value history

Assessed value moved from $405,400 (2011) to $741,300 (2026), up 83% over 15 years, per county tax rolls. The 2026 roll splits $741,300 into $218,700 land and $522,600 improvements.

Taxes

Permit history

Source: King County permit records (newest first).