506 21st St SE, Auburn, WA 98002

Multifamily · Auburn · Seattle-Bellevue metro, WA

One of 198 reachable multifamily buildings in Auburn. Larger than 84% of multifamily buildings in Auburn (median 13,000 SF), derived from assessor records.

Usable building area
52,552 SF, King County Assessor
County gross area
55,767 SF, King County Assessor
Excluded area
3,215 SF outside primary usable area
Lot size
111,530 SF, King County Assessor
Year built
1967, King County Assessor
Stories
2, King County Assessor
Predominant use
Apartment, King County Assessor
Units
74, King County Assessor
Assessed value
$10,597,000, per the King County Assessor (not a market appraisal)
Assessed value per usable SF
$201.65/SF, derived from assessor records
Usable area / lot
0.47, derived from assessor records
Vintage
1960s vintage
Zoning
R20, King County
County use code
Apartment

Nearby comparable buildings

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

Want to talk to the owner? makeme1031 delivers a private letter directly to the owner of record. We never publish the owner's identity or address.

Own this building?

Claim privately

Claiming is for you. Your mailing address is never shown; no offer reaches you unless you opt in.

Claimed owners can confirm facts, watch the estimate, and decide whether to reply.

Received a letter about this building? It came from a real buyer through makeme1031; claiming is how you reply privately, on your terms.

Claimed owners also get Portfolio Pulse: a monthly email tracking this building's value.

Claim or manage this building

Sale history and market context

MakeMe Estimate: $10.4M (estimated market value), with a likely range of $9.22M to $11.8M (half of recent verified sales in this segment landed inside that range). Based on 5 verified arm's-length comparable sales (through 2026-06-01). Not an appraisal. How this estimate works. About $140K per unit at the midpoint (74 units).

lower confidence: 0 comparable sales within 3 miles; nearest 6 mi.

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: Multifamily in Auburn

median verified sale $220.82/SF over the trailing 24 months; median $163,963 per unit; 3 sales in the last 12 months and 5 in 24 (newest verified sale 2025-12).

Computed from 199 verified arm's-length sales in King County public records (5 in the trailing 24 months). Free public records. Not an appraisal.

Last sold: 2007-03-14 for $3,544,740 (recorded arm's-length sale).

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$5M$10M$15M201120142017202020232026$10.4M$10.6MCounty 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. Diamonds: recorded arm's-length sales. Not an appraisal. How this estimate works.

Land, site, and value history

Assessed value moved from $3,300,000 (2011) to $10,597,000 (2026), up 221% over 15 years, per county tax rolls. The 2026 roll splits $10,597,000 into $1,226,800 land and $9,370,200 improvements.

Taxes

Permit history

Source: King County permit records (newest first).