505 S 336th St, Federal Way, WA 98003

Office · Federal Way · Seattle-Bellevue metro, WA

One of 189 reachable office buildings in Federal Way. Larger than 94% of office buildings in Federal Way (median 9,780 SF), derived from assessor records.

Usable building area
88,288 SF, King County Assessor
County gross area
93,658 SF, King County Assessor
Excluded area
5,370 SF outside primary usable area
Lot size
188,647 SF, King County Assessor
Year built
1982, King County Assessor
Stories
6, King County Assessor
Predominant use
Office Building, King County Assessor
Assessed value
$13,267,500, per the King County Assessor (not a market appraisal)
Assessed value per usable SF
$150.28/SF, derived from assessor records
Usable area / lot
0.47, derived from assessor records
Vintage
1980s vintage
Zoning
OP, 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: $14.9M (estimated market value), with a likely range of $13.2M to $17.2M (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: 1 comparable sale within 3 miles; nearest 0.3 mi. This property type carries wider measured error; treat the estimate as a starting point.

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 Federal Way

median verified sale $245.41/SF over the trailing 24 months; 2 sales in the last 12 months and 5 in 24 (newest verified sale 2026-03).

  • 2022: $234.46/SF median (6 sales)
  • 2023: $210.86/SF median (4 sales)
  • 2024: $369/SF median (6 sales)

Computed from 218 verified arm's-length sales in King County public records (5 in the trailing 24 months). Free public records. Not an appraisal.

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$14.9M$13.3MCounty 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 $10,852,500 (2011) to $13,267,500 (2026), up 22% over 15 years, per county tax rolls. The 2026 roll splits $13,267,500 into $2,641,000 land and $10,626,500 improvements.

Taxes

Permit history

Source: King County permit records (newest first).