Recent remodel sales, neighbors with lower values, deferred maintenance, or a double-digit jump while the market softened all point to overassessment.
Seattle homes are not all equal, but the Assessor's mass appraisal often treats them that way. The King County Assessor values more than 700,000 parcels from a desk, using sales models and aerial photos. Five patterns tend to show up when Fair Appeal pulls records on an overassessed home.
1. You bought the home for less than its current assessed value
If you closed in the last 12 to 18 months and paid less than the 2026 assessed value, the county's number is out of step with an actual ordinary market sale: your own. A recent purchase below the assessed value is one of the cleanest signals an assessment is out of line.
2. Your home backs onto an arterial, transit corridor, or commercial edge
Mass appraisal models weigh square footage and year built heavily. They miss what a human appraiser sees in 30 seconds: a bedroom window ten feet from Aurora, a back fence against a Link station, or a view of a warehouse roof. External obsolescence is routinely undervalued.
3. Your assessed value jumped 10% or more while the market softened
King County median home prices moved sideways through 2024 and into 2025, yet some neighborhoods saw double-digit assessment increases on the 2026 roll. If your value rose faster than your zip code's sale prices, the model is out of step with reality.
4. Nearby remodel sales pulled your value up
The Assessor's model uses recent sales to price your home, but it cannot always tell a down-to-studs remodel from a lived-in original. If three flipped homes sold on your block in 2024, your 2026 value may reflect their new kitchens rather than your 1978 one.
5. You have deferred maintenance the Assessor has not seen
Roof past its life, original single-pane windows, a foundation crack, rotted siding. None of this shows in aerial photos or permit records. If your home's physical condition is meaningfully worse than the model assumes, dated photos and repair estimates bring the assessed value down.
What to do next
If two or more signs apply, the 2026 assessment is worth a closer look before the filing window closes. FairAppeal pulls the full property record, evaluates the case, files the King County appeal, and only charges a percentage of first-year tax savings if the appeal wins. See the full 2026 King County deadline guide for the broader context, or the city-specific guides for Seattle and Bellevue.
Look up if you are overpaying on your King County home.
King County reassesses every home every year and leans on neighborhood comps without seeing condition.