26821 Maple Valley Black Diamond Rd SE, Maple Valley, WA 98038

Retail · Maple Valley · Seattle-Bellevue metro, WA

One of 52 reachable retail buildings in Maple Valley. Larger than 8% of retail buildings in Maple Valley (median 6,230 SF), derived from assessor records.

Usable building area
1,736 SF, King County Assessor
Lot size
20,604 SF, King County Assessor
Year built
1969, King County Assessor
Stories
1, King County Assessor
Predominant use
Service Station, King County Assessor
Assessed value
$1,101,000, per the King County Assessor (not a market appraisal)
Assessed value per usable SF
$634.22/SF, derived from assessor records
Usable area / lot
0.08, derived from assessor records
Vintage
1960s vintage
Zoning
TC, King County
County use code
Service Station

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: $1.67M (estimated market value), with a likely range of $1.19M to $2.09M (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: 0 comparable sales within 3 miles; nearest 3.3 mi. This property type carries wider measured error; treat the estimate as a starting point. Comparable-sale caveat: the estimate is 83% above the $525.11/SF median of the shown comparable sales.

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.

Last sold: 2007-11-07 for $765,182 (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$1.67M$1.1MCounty 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 $757,200 (2011) to $1,101,000 (2026), up 45% over 15 years, per county tax rolls. The 2026 roll splits $1,101,000 into $659,300 land and $441,700 improvements.

Taxes

Permit history

Source: King County permit records (newest first).