Westwood Plaza Condominium
Multifamily Housing in Seattle, WA · 2421 SW TRENTON ST · 98106
At a glance
Westwood Plaza Condominium is a 35,122-square-foot multifamily housing building at 2421 SW TRENTON ST in Seattle, Washington, built in 1981. In its 2025 Seattle benchmarking disclosure it reported an ENERGY STAR score of 69 out of 100 (grade C), a site energy-use intensity of 27.0 kBtu/ft² and 5 tCO₂e of greenhouse-gas emissions. That score is higher than 18% of the 1,652 scored multifamily housing buildings in Seattle.
Seattle Energy Benchmarking Ordinance (SMC 22.920) · reporting year 2025
Benchmarking record
| Field | Value |
|---|---|
| ENERGY STAR score | 69 (band C) |
| Site EUI | 27.0 kBtu/ft² |
| Source EUI | 75.6 kBtu/ft² |
| GHG emissions | 5 tCO₂e |
| GHG intensity | 0.1 kgCO₂e/ft² |
| Electricity | 254,239 kWh |
| Gross floor area | 35,122 sq ft |
| Source record | seattle:26026:2025 |
The disclosure history
Year over year
| Year | Score | Δ | Site EUI | GHG emissions |
|---|---|---|---|---|
| 2025latest | 69 | +1 | 27.0 kBtu/ft² | 5 tCO₂e |
| 2024 | 68 | +3 | 26.9 kBtu/ft² | 5 tCO₂e |
| 2023 | 65 | -5 | 28.1 kBtu/ft² | 5 tCO₂e |
| 2022 | 70 | +4 | 28.1 kBtu/ft² | 5 tCO₂e |
| 2021 | 66 | +8 | 28.4 kBtu/ft² | 5 tCO₂e |
| 2020 | 58 | +1 | 28.7 kBtu/ft² | 5 tCO₂e |
| 2019 | 57 | -1 | 29.1 kBtu/ft² | 5 tCO₂e |
| 2018 | 58 | +20 | 28.7 kBtu/ft² | 5 tCO₂e |
| 2017 | 38 | -5 | 34.4 kBtu/ft² | 6 tCO₂e |
| 2016 | 43 | -21 | 29.2 kBtu/ft² | 5 tCO₂e |
| 2015 | 64 | 27.8 kBtu/ft² | 5 tCO₂e |
Compliance context
Seattle Energy Benchmarking Ordinance (SMC 22.920)
Seattle's Building Emissions Performance Standard (adopted 2023) applies to buildings over 20,000 sq ft: benchmarking verification is due 2027–2030 and initial emissions targets 2031–2035, reaching net zero by 2041–2050, with fines for non-compliance.
Ownership
No owning organisation shown. Names of private individuals in the disclosure are not published here.
Own or manage this building? Claim it to correct the record and get compliance alerts.
Location
- Address
- 2421 SW TRENTON ST
- City
- Seattle
- State
- Washington
- ZIP
- 98106
- Coordinates
- 47.52451, -122.36424
Within ~1 km
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See also: most efficient in Seattle · biggest emitters
How does Westwood Plaza Condominium compare with other multifamily housing buildings in Seattle?
The latest disclosures cover 1,971 multifamily housing buildings in Seattle, out of 3,871 buildings citywide. Westwood Plaza Condominium's ENERGY STAR score of 69 compares with an average of 83 across the 1,652 that report a score; it scores higher than 18% of them and lower than 82%. Its site EUI of 27.0 kBtu/ft² is about 23% below the average of 34.9 kBtu/ft² — it uses less energy per square foot than the typical building in that group. Its emissions intensity of 0.1 kgCO₂e/ft² is about 79% below the group average of 0.7 kgCO₂e/ft².
At 35,122 sq ft, it is about 59% below the average floor area of 86,468 sq ft for those buildings. Its 1981 construction date is close to the group's average year built (1983). Across all 24 jurisdictions BuildingCensus covers, the 59,945 multifamily housing buildings average an ENERGY STAR score of 70 and a site EUI of 59.0 kBtu/ft².
How has Westwood Plaza Condominium's energy performance changed over time?
BuildingCensus holds 11 Seattle disclosures for Westwood Plaza Condominium, covering report years 2015–2025. Its ENERGY STAR score went from 64 in 2015 to 69 in 2025 (+5 points); its best year on file was 2022, at 70. Site EUI moved from 27.8 kBtu/ft² (2015) to 27.0 kBtu/ft² (2025), a 3% decrease. Reported emissions went from 5 tCO₂e to 5 tCO₂e over the same span (down 4%).
What does an ENERGY STAR score of 69 mean?
ENERGY STAR scores run from 1 to 100 and are computed by the EPA's Portfolio Manager as a percentile against similar buildings nationwide, adjusted for climate, size and use: a score of 69 means the building performs better than about 69% of its national peers. BuildingCensus bands the score into report-card grades; 69 falls in band C — below median (55–69). It sits 6 points below 75, the threshold for ENERGY STAR certification. In Seattle, 69% of scored buildings are at 75 or above.
Site energy-use intensity (EUI) is the energy a building uses on site in a year divided by its floor area, in thousand Btu per square foot — lower is more efficient. Westwood Plaza Condominium's 27.0 kBtu/ft² across 35,122 sq ft works out to about 0.9 billion Btu (278 MWh-equivalent) in 2025. Its source EUI of 75.6 kBtu/ft² also counts the energy lost generating and delivering that power, which is why it is higher. The disclosure also reports 254,239 kWh of electricity for the year.
Which law requires Westwood Plaza Condominium to report its energy use?
Westwood Plaza Condominium reports under the Seattle Energy Benchmarking Ordinance (SMC 22.920), the legal basis of Seattle's Building Energy Benchmarking program, which publishes each covered building's annual benchmarking results. The record shown here is the report-year 2025 disclosure (source record seattle:26026:2025). Seattle's Building Emissions Performance Standard (adopted 2023) applies to buildings over 20,000 sq ft: benchmarking verification is due 2027–2030 and initial emissions targets 2031–2035, reaching net zero by 2041–2050, with fines for non-compliance.
More multifamily housing buildings in Seattle
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- Park Hill Apts· 35,000 sq ft · score 72 (B)
- Rivendell Apts· 34,962 sq ft · score 99 (A)
- Edison Condominiums· 34,960 sq ft · score 99 (A)
- Howell Street Apartments· 34,924 sq ft · score 98 (A)
- Fix Building The Condominium· 34,909 sq ft · score 99 (A)
- Multifamily Housing buildings in Seattle· 1,971 benchmarked
- All Seattle benchmarked buildings· Seattle Energy Benchmarking Ordinance (SMC 22.920)
- Most efficient large buildings in Seattle
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- Biggest emitters in Seattle
Frequently asked questions
What is Westwood Plaza Condominium's energy grade?
Westwood Plaza Condominium scores 69 out of 100 on ENERGY STAR — band C, below median (55–69) — in its 2025 Seattle disclosure. Scores are national percentiles against similar buildings; 75+ qualifies for ENERGY STAR certification.
How much energy does Westwood Plaza Condominium use?
Its 2025 site energy-use intensity was 27.0 kBtu/ft² (75.6 kBtu/ft² source) across 35,122 sq ft, including 254,239 kWh of electricity.
What are Westwood Plaza Condominium's carbon emissions?
Westwood Plaza Condominium reported 5 tCO₂e of greenhouse-gas emissions (0.1 kgCO₂e/ft²) for 2025.
Where is Westwood Plaza Condominium?
Westwood Plaza Condominium is at 2421 SW TRENTON ST, in Seattle, Washington 98106. Its coordinates are 47.52451, -122.36424 (latitude, longitude), as published in the Building Energy Benchmarking file.
How big is Westwood Plaza Condominium and when was it built?
Westwood Plaza Condominium has 35,122 sq ft of gross floor area, as reported in its 2025 disclosure. The disclosure lists 1981 as its year built. It is classed as multifamily housing.
Is Westwood Plaza Condominium covered by the Seattle Energy Benchmarking Ordinance (SMC 22.920)?
Yes — it appears in the 2025 Building Energy Benchmarking disclosure, which lists the buildings reporting under the Seattle Energy Benchmarking Ordinance (SMC 22.920).
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About this data
Source: Building Energy Benchmarking (Seattle Energy Benchmarking Ordinance (SMC 22.920)), as published October 2, 2026. See the methodology for how records are matched, cleaned and scored.
Cite as: BuildingCensus, “Westwood Plaza Condominium, Seattle, Washington — 2025 benchmarking disclosure”, https://buildingcensus.com/buildings/seattle/westwood-plaza-condominium-93178a7c (data as of October 2, 2026).