BuildingCensus
B

Westerly Condominium

Multifamily Housing in Seattle, WA · 4540 45TH AVE SW · 98116

At a glance

Westerly Condominium is a 20,407-square-foot multifamily housing building at 4540 45TH AVE SW in Seattle, Washington, built in 1989. In its 2025 Seattle benchmarking disclosure it reported an ENERGY STAR score of 82 out of 100 (grade B), a site energy-use intensity of 29.5 kBtu/ft² and 3 tCO₂e of greenhouse-gas emissions. That score is higher than 32% of the 1,652 scored multifamily housing buildings in Seattle.

ENERGY STAR score
82
band B · 2025
Site EUI
29.5
kBtu/ft²
GHG emissions
3
tCO₂e
GHG intensity
0.2
kgCO₂e/ft²
Floor area
20,407
sq ft
Year built
1989
vintage
◆ Loading map…
85–10070–8455–691–54
This entry + 6 nearby

Seattle Energy Benchmarking Ordinance (SMC 22.920) · reporting year 2025

Benchmarking record

FieldValue
ENERGY STAR score82 (band B)
Site EUI29.5 kBtu/ft²
Source EUI82.7 kBtu/ft²
GHG emissions3 tCO₂e
GHG intensity0.2 kgCO₂e/ft²
Electricity147,169 kWh
Gross floor area20,407 sq ft
Source recordseattle:25883:2025

The disclosure history

Year over year

YearScoreΔSite EUIGHG emissions
2025latest82-129.5 kBtu/ft²3 tCO₂e
202483-329.0 kBtu/ft²3 tCO₂e
202386+328.9 kBtu/ft²3 tCO₂e
202283+230.5 kBtu/ft²3 tCO₂e
202181+530.7 kBtu/ft²3 tCO₂e
202076-331.0 kBtu/ft²3 tCO₂e
201979-530.3 kBtu/ft²3 tCO₂e
201884-628.6 kBtu/ft²3 tCO₂e
201790+1726.8 kBtu/ft²3 tCO₂e
201673+5329.9 kBtu/ft²3 tCO₂e
20152028.9 kBtu/ft²3 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.

Program details →

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
4540 45TH AVE SW
State
Washington
ZIP
98116
Coordinates
47.56178, -122.38910

Within ~1 km

Nearby benchmarked buildings

See also: most efficient in Seattle · biggest emitters

How does Westerly 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. Westerly Condominium's ENERGY STAR score of 82 compares with an average of 83 across the 1,652 that report a score; it scores higher than 32% of them and lower than 66%. Its site EUI of 29.5 kBtu/ft² is about 15% 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 0.2 kgCO₂e/ft² is about 76% below the group average of 0.7 kgCO₂e/ft².

At 20,407 sq ft, it is about 76% below the average floor area of 86,468 sq ft for those buildings. It was built in 1989, 6 years later than 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 Westerly Condominium's energy performance changed over time?

BuildingCensus holds 11 Seattle disclosures for Westerly Condominium, covering report years 2015–2025. Its ENERGY STAR score went from 20 in 2015 to 82 in 2025 (+62 points); its best year on file was 2017, at 90. Site EUI moved from 28.9 kBtu/ft² (2015) to 29.5 kBtu/ft² (2025), an 2% increase. Reported emissions went from 3 tCO₂e to 3 tCO₂e over the same span (up 3%).

What does an ENERGY STAR score of 82 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 82 means the building performs better than about 82% of its national peers. BuildingCensus bands the score into report-card grades; 82 falls in band B — above median (70–84). Scores of 75 or higher meet the threshold for ENERGY STAR certification; certification itself is a separate, verified application that the disclosure does not record. 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. Westerly Condominium's 29.5 kBtu/ft² across 20,407 sq ft works out to about 0.6 billion Btu (176 MWh-equivalent) in 2025. Its source EUI of 82.7 kBtu/ft² also counts the energy lost generating and delivering that power, which is why it is higher. The disclosure also reports 147,169 kWh of electricity for the year.

Which law requires Westerly Condominium to report its energy use?

Westerly 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:25883:2025). 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

Frequently asked questions

What is Westerly Condominium's energy grade?

Westerly Condominium scores 82 out of 100 on ENERGY STAR — band B, above median (70–84) — in its 2025 Seattle disclosure. Scores are national percentiles against similar buildings; 75+ qualifies for ENERGY STAR certification.

How much energy does Westerly Condominium use?

Its 2025 site energy-use intensity was 29.5 kBtu/ft² (82.7 kBtu/ft² source) across 20,407 sq ft, including 147,169 kWh of electricity.

What are Westerly Condominium's carbon emissions?

Westerly Condominium reported 3 tCO₂e of greenhouse-gas emissions (0.2 kgCO₂e/ft²) for 2025.

Where is Westerly Condominium?

Westerly Condominium is at 4540 45TH AVE SW, in Seattle, Washington 98116. Its coordinates are 47.56178, -122.38910 (latitude, longitude), as published in the Building Energy Benchmarking file.

How big is Westerly Condominium and when was it built?

Westerly Condominium has 20,407 sq ft of gross floor area, as reported in its 2025 disclosure. The disclosure lists 1989 as its year built. It is classed as multifamily housing.

Is Westerly 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).

Working with Seattle building benchmarking records? Pro adds alerts, change history and CSV export ($49/mo); Enterprise adds full national files, the API and an MCP server for AI tools.

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, “Westerly Condominium, Seattle, Washington — 2025 benchmarking disclosure”, https://buildingcensus.com/buildings/seattle/westerly-condominium-a4fd9a52 (data as of October 2, 2026).