At a glance
1101 Westlake is a 185,116-square-foot office building at 1101 WESTLAKE AVE N in Seattle, Washington, built in 2015. In its 2025 Seattle benchmarking disclosure it reported a site energy-use intensity of 24.3 kBtu/ft² and 23 tCO₂e of greenhouse-gas emissions.
Seattle Energy Benchmarking Ordinance (SMC 22.920) · reporting year 2025
Benchmarking record
| Field | Value |
|---|---|
| ENERGY STAR score | — |
| Site EUI | 24.3 kBtu/ft² |
| Source EUI | 67.6 kBtu/ft² |
| GHG emissions | 23 tCO₂e |
| GHG intensity | 0.1 kgCO₂e/ft² |
| Electricity | 1,141,757 kWh |
| Gross floor area | 185,116 sq ft |
| Source record | seattle:50048:2025 |
The disclosure history
Year over year
| Year | Score | Δ | Site EUI | GHG emissions |
|---|---|---|---|---|
| 2025latest | — | 24.3 kBtu/ft² | 23 tCO₂e | |
| 2024 | — | 29.5 kBtu/ft² | 41 tCO₂e | |
| 2023 | — | 67.4 kBtu/ft² | 189 tCO₂e | |
| 2022 | 53 | -47 | 88.4 kBtu/ft² | 182 tCO₂e |
| 2021 | 100 | +29 | 11.5 kBtu/ft² | 42 tCO₂e |
| 2020 | 71 | ±0 | 61.6 kBtu/ft² | 107 tCO₂e |
| 2019 | 71 | 75.8 kBtu/ft² | 104 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.
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Location
- Address
- 1101 WESTLAKE AVE N
- City
- Seattle
- State
- Washington
- ZIP
- 98109
- Coordinates
- 47.62908, -122.34140
Within ~1 km
Nearby benchmarked buildings
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- Bill & Melinda Gates Foundationscore 73
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- Ascent Slu And Marlowescore 99
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- Block 31 - Googlescore 89
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See also: most efficient in Seattle · biggest emitters
How does 1101 Westlake compare with other office buildings in Seattle?
The latest disclosures cover 497 office buildings in Seattle, out of 3,871 buildings citywide. Its site EUI of 24.3 kBtu/ft² is about half of the average of 44.8 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 80% below the group average of 0.7 kgCO₂e/ft².
At 185,116 sq ft, it is roughly in line with the average floor area of 196,452 sq ft for those buildings. It was built in 2015, 50 years later than the group's average year built (1965). Across all 24 jurisdictions BuildingCensus covers, the 15,264 office buildings average an ENERGY STAR score of 73 and a site EUI of 59.3 kBtu/ft².
How has 1101 Westlake's energy performance changed over time?
BuildingCensus holds 7 Seattle disclosures for 1101 Westlake, covering report years 2019–2025. Its ENERGY STAR score went from 71 in 2019 to 53 in 2022 (-18 points); its best year on file was 2021, at 100. Site EUI moved from 75.8 kBtu/ft² (2019) to 24.3 kBtu/ft² (2025), a 68% decrease. Reported emissions went from 104 tCO₂e to 23 tCO₂e over the same span (down 78%).
What does a site EUI of 24.3 kBtu/ft² mean?
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. 1101 Westlake's 24.3 kBtu/ft² across 185,116 sq ft works out to about 4.5 billion Btu (1,318 MWh-equivalent) in 2025. Its source EUI of 67.6 kBtu/ft² also counts the energy lost generating and delivering that power, which is why it is higher. The disclosure also reports 1,141,757 kWh of electricity for the year.
Which law requires 1101 Westlake to report its energy use?
1101 Westlake 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:50048:2025). 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 office buildings in Seattle
- Interurban Exchange Ii (Wainwright)· 184,482 sq ft · score 94 (A)
- 333 Elliott· 183,964 sq ft · score 87 (A)
- Yale & Thomas· 183,578 sq ft
- 5th & Jackson Building· 181,694 sq ft · EUI 22.2 kBtu/ft²
- Magnuson Bldg 2, Conservation Corps· 178,196 sq ft · score 100 (A)
- Republican Building· 176,532 sq ft
- Office buildings in Seattle· 497 benchmarked
- All Seattle benchmarked buildings· Seattle Energy Benchmarking Ordinance (SMC 22.920)
- Most efficient large buildings in Seattle
- Least efficient large buildings in Seattle
- Biggest emitters in Seattle
Frequently asked questions
What is 1101 Westlake's energy grade?
1101 Westlake did not report an ENERGY STAR score in its 2025 disclosure, but its site energy-use intensity was 24.3 kBtu/ft².
How much energy does 1101 Westlake use?
Its 2025 site energy-use intensity was 24.3 kBtu/ft² (67.6 kBtu/ft² source) across 185,116 sq ft, including 1,141,757 kWh of electricity.
What are 1101 Westlake's carbon emissions?
1101 Westlake reported 23 tCO₂e of greenhouse-gas emissions (0.1 kgCO₂e/ft²) for 2025.
Where is 1101 Westlake?
1101 Westlake is at 1101 WESTLAKE AVE N, in Seattle, Washington 98109. Its coordinates are 47.62908, -122.34140 (latitude, longitude), as published in the Building Energy Benchmarking file.
How big is 1101 Westlake and when was it built?
1101 Westlake has 185,116 sq ft of gross floor area, as reported in its 2025 disclosure. The disclosure lists 2015 as its year built. It is classed as office.
Is 1101 Westlake 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, “1101 Westlake, Seattle, Washington — 2025 benchmarking disclosure”, https://buildingcensus.com/buildings/seattle/1101-westlake-ed0d3ecc (data as of October 2, 2026).