520 Williams Ave S, Renton, WA 98057

Multifamily · Renton · Seattle-Bellevue metro, WA

One of 324 reachable multifamily buildings in Renton. Larger than 42% of multifamily buildings in Renton (median 7,257 SF), derived from assessor records.

Usable building area
5,430 SF, King County Assessor
County gross area
6,523 SF, King County Assessor
Excluded area
1,093 SF outside primary usable area
Lot size
5,500 SF, King County Assessor
Year built
2016, King County Assessor
Stories
3, King County Assessor
Predominant use
4-Plex, King County Assessor
Units
4, King County Assessor
Assessed value
$1,764,000, per the King County Assessor (not a market appraisal)
Assessed value per usable SF
$324.86/SF, derived from assessor records
Usable area / lot
0.99, derived from assessor records
Vintage
2010s vintage
Zoning
R-14, King County
County use code
4-Plex

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: $1.73M (estimated market value), with a likely range of $1.54M to $1.98M (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 $433K per unit at the midpoint (4 units).

lower confidence: 3 comparable sales within 3 miles; nearest 0.9 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 Renton

median verified sale $328.78/SF over the trailing 24 months; median $250,000 per unit; 8 sales in the last 12 months and 15 in 24 (newest verified sale 2025-12); the middle 80% of recent sales traded at 0.93x to 1.44x their county assessed value, median 1.11x (15 sales with usable county values).

  • 2021: $322.52/SF median (12 sales)
  • 2022: $339.87/SF median (9 sales)
  • 2023: $283.28/SF median (5 sales)
  • 2024: $328.78/SF median (7 sales)
  • 2025: $292.97/SF median (7 sales)

This estimate sits at 0.98x county assessed value, the 20th percentile of those recent sale premiums.

Computed from 463 verified arm's-length sales in King County public records (15 in the trailing 24 months). Free public records. Not an appraisal.

Last sold: 2007-06-11 for $260,000 (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$1M$2M$3M201120142017202020232026$1.73M$1.76MCounty 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 $172,000 (2011) to $1,764,000 (2026), up 926% over 15 years, per county tax rolls. The 2026 roll splits $1,764,000 into $201,000 land and $1,563,000 improvements.

Taxes

Permit history

Source: King County permit records (newest first).