Engine-derived ROI data from 5 representative Seattle-area properties. Methodology transparent below. CC-BY 4.0, journalists, CPAs, and researchers may cite this dataset with attribution.
Important framing: These are engine outputs for representative fixture scenarios, not predictions about any specific property. The cost segregation engine takes real property data (address, year built, square footage, renovation history, assessor records) and produces a study tailored to your actual property. The aggregate numbers shown here describe the Seattle market's general profile; your specific results will reflect your specific property.
Each fixture was run through the Cost Seg Smart engine, the same engine that produces real customer studies. Numbers below are reproducible from cities/seattle.json via scripts/run_city_stats.py.
| Property | Neighborhood | Price | Basis | Land % | 5-yr | 15-yr | Reclass % | Y1 fed savings @ 37% |
|---|---|---|---|---|---|---|---|---|
| Capitol Hill Craftsman Flip SFR · Built 1918 |
Capitol Hill / Central District | $925,000 | $560,550 | 39.4% | $50,443 | $40,930 | 16.3% | $33,808 |
| Ballard SFR + Detached ADU SFR · Built 1940 |
Ballard / Fremont (Northwest Seattle) | $875,000 | $524,388 | 40.1% | $50,775 | $34,397 | 16.2% | $31,514 |
| West Seattle SFR Rental SFR · Built 1962 |
West Seattle | $785,000 | $475,710 | 39.4% | $43,062 | $32,149 | 15.8% | $27,828 |
| Bellevue Eastside Condo CONDO · Built 2014 |
Bellevue / Kirkland (Eastside) | $1,185,000 | $556,116 | 53.1% | $58,241 | $5,212 | 11.4% | $23,477 |
| Renton Suburban Fourplex FOURPLEX · Built 1985 |
Renton / Kent (suburban King County south) | $685,000 | $485,734 | 29.1% | $64,068 | $30,536 | 19.5% | $35,003 |
| Engine property type | Fixtures | Median reclass % | Min | Max |
|---|---|---|---|---|
| SFR | 3 | 16.2% | 15.8% | 16.3% |
| CONDO | 1 | 11.4% | 11.4% | 11.4% |
| FOURPLEX | 1 | 19.5% | 19.5% | 19.5% |
"STR" denotes residential property operating as a short-term rental, the engine applies an FF&E density uplift not captured in the LTR (long-term rental) treatment.
| Neighborhood | Typical value | Typical land allocation | Profile note |
|---|---|---|---|
| Capitol Hill / Central District | $925,000 | ~32% | Dense urban residential with 1910s–1920s Craftsman stock and post-2010 townhome new builds. Higher land allocation. Fix-and-flip and small-MF activity. |
| Ballard / Fremont (Northwest Seattle) | $875,000 | ~28% | 1920s–1950s SFR with heavy post-2010 renovation. ADU expansion since 2019 zoning reform. Mid-tier land allocation. |
| West Seattle | $785,000 | ~26% | SFR-dominant residential west of downtown. Lower land allocation than Capitol Hill. Mix of fix-and-flip and ADU expansion. |
| Bellevue / Kirkland (Eastside) | $1,185,000 | ~30% | Tech-employer-anchored Eastside residential. Higher absolute basis. Mid-rise condo and SFR mix. Stronger corporate-relocation LTR demand. |
| Renton / Kent (suburban King County south) | $525,000 | ~20% | Lower-cost SFR rental market south of Seattle. Lower land allocation. Strong BRRRR and build-to-rent activity. Lighter STR regulation than Seattle proper. |
The "typical land allocation" column reflects baseline patterns for each sub-market based on county assessor records and statistical modeling. For specific properties where reconstruction cost (RSMeans 2024 component build-up adjusted for time and geography) exceeds 2.0× the implied depreciable basis after subtracting the baseline land, the engine applies a premium land floor (~50%) to keep the study within audit-defensible territory. This typically affects ultra-premium resort inventory (ski-in/ski-out, beachfront, view-premium properties), where land scarcity premium dominates the purchase price. The per-fixture table above shows the actual land_source used by the engine for each fixture, values of statistical_premium_floor indicate the premium-floor mechanism was applied.
The takeaway: typical neighborhood allocations describe the market baseline. Individual property results depend on specific reconstruction-cost-vs-purchase-price ratios, and ultra-premium product may show higher land allocation in the engine output than the neighborhood typical.
Washington has no state individual income tax, federal §168(k) bonus depreciation is the entire income-tax story for Seattle investors. But the WA tax landscape has two distinct features: a 7% capital gains tax on long-term gains above $250K (rental real estate generally exempt from this specific tax), and the B&O excise tax on rental business gross receipts (varies by rental classification). Neither affects the cost-seg study itself, engine output is unchanged, but both should factor into multi-year operating-economics modeling around the Year-1 cost-seg deduction.
Decoupling: Verify B&O tax treatment of your specific rental activity with your CPA, WA B&O classification rules vary by property type and lease structure.
State income tax structure: No individual income tax. 7% Washington capital gains tax applies on long-term capital gains above $250K threshold (rental property gains exempt from this specific tax). Business & Occupation (B&O) tax applies to gross rental receipts at varying rates.
Verify with your CPA. State tax conformity for federal §168(k) is adjusted frequently. Framing reflects our understanding as of May 2026, verify current-year treatment with a qualified tax professional.
Every figure on this page is reproducible. The pipeline:
cities/seattle.json under the engine_fixtures array, each with address, property type, purchase price, year built, square footage, and STR/LTR flag.scripts/run_city_stats.py instantiates a PropertyInput for each fixture and calls engine.run_study(), the same path that produces a real customer study.For full methodology details including QC validation, reconciliation logic, and audit-defense documentation, see costsegsmart.com/methodology.
This dataset is licensed under the Creative Commons Attribution 4.0 International License. You may republish, remix, or extend this data for any purpose with attribution. Suggested citation format:
Cost Seg Smart Research Team. (2026). "Seattle, WA Cost Segregation Benchmarks 2026." Cost Seg Smart. 5 representative fixtures. Retrieved from https://seattlecostseg.com/data/seattle-cost-seg-stats/
For interview requests, additional data slices, or related questions: [email protected].