421 SW Ambaum Blvd, Burien, WA 98166

Multifamily · Burien · Seattle-Bellevue metro, WA

One of 281 reachable multifamily buildings in Burien. Larger than 12% of multifamily buildings in Burien (median 10,533 SF), derived from assessor records.

Usable building area
4,200 SF, King County Assessor
County gross area
4,444 SF, King County Assessor
Excluded area
244 SF outside primary usable area
Lot size
8,553 SF, King County Assessor
Year built
1960, King County Assessor
Stories
2, King County Assessor
Predominant use
Apartment, King County Assessor
Units
6, King County Assessor
Assessed value
$1,100,000, per the King County Assessor (not a market appraisal)
Assessed value per usable SF
$261.90/SF, derived from assessor records
Usable area / lot
0.49, derived from assessor records
Vintage
1960s vintage
Zoning
R4, King County
County use code
Apartment

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: $1.15M (estimated market value), with a likely range of $1.02M to $1.31M (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. About $192K per unit at the midpoint (6 units).

moderate confidence: 8 comparable sales within 3 miles; nearest 0.1 mi. Recent sale check: this building sold for $1,098,500 in 2023; the estimate is about 5% 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. The strongest 5 of 8 nearby verified sales are shown. Buyer and seller names are withheld. Get this data via API.

Market context: Multifamily in Burien

median verified sale $241.87/SF over the trailing 24 months; median $185,567 per unit; 13 sales in the last 12 months and 19 in 24 (newest verified sale 2026-05); the middle 80% of recent sales traded at 0.73x to 1.32x their county assessed value, median 0.97x (19 sales with usable county values).

  • 2022: $251.87/SF median (11 sales)
  • 2023: $244.24/SF median (8 sales)
  • 2024: $184.24/SF median (5 sales)
  • 2025: $241.87/SF median (10 sales)
  • 2026 YTD: $288.83/SF median (6 sales)

This estimate sits at 1.04x county assessed value, the 68th percentile of those recent sale premiums.

Computed from 369 verified arm's-length sales in King County public records (19 in the trailing 24 months). Free public records. Not an appraisal.

Last sold: 2023-01-04 for $1,098,500 (recorded arm's-length sale).

Current ownership dates to 2023 (about 3 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$1.5M201120142017202020232026$784KLast sold $1.1M · 2023$1.15M$1.1MCounty 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 $401,000 (2011) to $1,100,000 (2026), up 174% over 15 years, per county tax rolls. The 2026 roll splits $1,100,000 into $153,900 land and $946,100 improvements.

Taxes

Permit history

Source: King County permit records (newest first).