At a glance
635 ELLIOTT - SOUTH BUILDING is a 291,176-square-foot office building at 635 ELLIOTT AVE W in Seattle, Washington, built in 2009. In its 2024 Seattle benchmarking disclosure it reported an ENERGY STAR score of 65 out of 100 (grade C), a site energy-use intensity of 44.9 kBtu/ft² and 63 tCO₂e of greenhouse-gas emissions. That score is higher than 20% of the 378 scored office buildings in Seattle.
Seattle Energy Benchmarking Ordinance (SMC 22.920) · reporting year 2024
Benchmarking record
| Field | Value |
|---|---|
| ENERGY STAR score | 65 (band C) |
| Site EUI | 44.9 kBtu/ft² |
| Source EUI | 123.2 kBtu/ft² |
| GHG emissions | 63 tCO₂e |
| GHG intensity | 0.3 kgCO₂e/ft² |
| Electricity | 2,431,775 kWh |
| Natural gas | 2,846 therms |
| Gross floor area | 291,176 sq ft |
| Source record | seattle:597:2024 |
The disclosure history
Year over year
| Year | Score | Δ | Site EUI | GHG emissions |
|---|---|---|---|---|
| 2024latest | 65 | ±0 | 44.9 kBtu/ft² | 63 tCO₂e |
| 2023 | 65 | -3 | 45.7 kBtu/ft² | 59 tCO₂e |
| 2022 | 68 | -17 | 44.4 kBtu/ft² | 52 tCO₂e |
| 2021 | 85 | +1 | 37.4 kBtu/ft² | 41 tCO₂e |
| 2020 | 84 | -3 | 38.3 kBtu/ft² | 50 tCO₂e |
| 2019 | 87 | -2 | 40.1 kBtu/ft² | 58 tCO₂e |
| 2018 | 89 | -1 | 41.6 kBtu/ft² | 61 tCO₂e |
| 2017 | 90 | -8 | 43.8 kBtu/ft² | 64 tCO₂e |
| 2016 | 98 | -1 | 35.5 kBtu/ft² | 42 tCO₂e |
| 2015 | 99 | 31.2 kBtu/ft² | 35 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
- 635 ELLIOTT AVE W
- City
- Seattle
- State
- Washington
- ZIP
- 98119
- Coordinates
- 47.62520, -122.36737
Within ~1 km
Nearby benchmarked buildings
- Expedia - Campusscore 86
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- Avalon Queen Annescore 98
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- Elliott Bay Office Parkscore 97
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- 645 Elliott - North Buildingscore —
Mixed Use Property · 242,686 sq ft
- 3rd And Harrisonscore —
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See also: most efficient in Seattle · biggest emitters
How does 635 ELLIOTT - SOUTH BUILDING compare with other office buildings in Seattle?
The latest disclosures cover 497 office buildings in Seattle, out of 3,871 buildings citywide. 635 ELLIOTT - SOUTH BUILDING's ENERGY STAR score of 65 compares with an average of 76 across the 378 that report a score; it scores higher than 20% of them and lower than 79%. Its site EUI of 44.9 kBtu/ft² is roughly in line with the average of 44.8 kBtu/ft². Its emissions intensity of 0.3 kgCO₂e/ft² is about half of the group average of 0.7 kgCO₂e/ft².
At 291,176 sq ft, it is about 48% above the average floor area of 196,452 sq ft for those buildings. It was built in 2009, 44 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 635 ELLIOTT - SOUTH BUILDING's energy performance changed over time?
BuildingCensus holds 10 Seattle disclosures for 635 ELLIOTT - SOUTH BUILDING, covering report years 2015–2024. Its ENERGY STAR score went from 99 in 2015 to 65 in 2024 (-34 points); its best year on file was 2015, at 99. Site EUI moved from 31.2 kBtu/ft² (2015) to 44.9 kBtu/ft² (2024), an 44% increase. Reported emissions went from 35 tCO₂e to 63 tCO₂e over the same span (up 79%).
What does an ENERGY STAR score of 65 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 65 means the building performs better than about 65% of its national peers. BuildingCensus bands the score into report-card grades; 65 falls in band C — below median (55–69). It sits 10 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. 635 ELLIOTT - SOUTH BUILDING's 44.9 kBtu/ft² across 291,176 sq ft works out to about 13.1 billion Btu (3,832 MWh-equivalent) in 2024. Its source EUI of 123.2 kBtu/ft² also counts the energy lost generating and delivering that power, which is why it is higher. The disclosure also reports 2,431,775 kWh of electricity and 2,846 therms of natural gas for the year.
Which law requires 635 ELLIOTT - SOUTH BUILDING to report its energy use?
635 ELLIOTT - SOUTH BUILDING 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 2024 disclosure (source record seattle:597:2024). 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
- 1000 Denny Way Building· 287,819 sq ft · score 10 (D)
- 5th & Bell Building· 287,471 sq ft · score 78 (B)
- Adobe Building-801-N 34 St.· 280,957 sq ft · score 74 (B)
- 15th & Market Building (Includes Target Store)· 279,102 sq ft · score 91 (A)
- 3131 Elliott Bldg· 277,486 sq ft · score 77 (B)
- 2323 Elliott - Parking & Office· 275,982 sq ft · EUI 11.5 kBtu/ft²
- 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 635 ELLIOTT - SOUTH BUILDING's energy grade?
635 ELLIOTT - SOUTH BUILDING scores 65 out of 100 on ENERGY STAR — band C, below median (55–69) — in its 2024 Seattle disclosure. Scores are national percentiles against similar buildings; 75+ qualifies for ENERGY STAR certification.
How much energy does 635 ELLIOTT - SOUTH BUILDING use?
Its 2024 site energy-use intensity was 44.9 kBtu/ft² (123.2 kBtu/ft² source) across 291,176 sq ft, including 2,431,775 kWh of electricity and 2,846 therms of natural gas.
What are 635 ELLIOTT - SOUTH BUILDING's carbon emissions?
635 ELLIOTT - SOUTH BUILDING reported 63 tCO₂e of greenhouse-gas emissions (0.3 kgCO₂e/ft²) for 2024.
Where is 635 ELLIOTT - SOUTH BUILDING?
635 ELLIOTT - SOUTH BUILDING is at 635 ELLIOTT AVE W, in Seattle, Washington 98119. Its coordinates are 47.62520, -122.36737 (latitude, longitude), as published in the Building Energy Benchmarking file.
How big is 635 ELLIOTT - SOUTH BUILDING and when was it built?
635 ELLIOTT - SOUTH BUILDING has 291,176 sq ft of gross floor area, as reported in its 2024 disclosure. The disclosure lists 2009 as its year built. It is classed as office.
Is 635 ELLIOTT - SOUTH BUILDING covered by the Seattle Energy Benchmarking Ordinance (SMC 22.920)?
Yes — it appears in the 2024 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, “635 ELLIOTT - SOUTH BUILDING, Seattle, Washington — 2024 benchmarking disclosure”, https://buildingcensus.com/buildings/seattle/635-elliott-south-building-9bbcacb4 (data as of October 2, 2026).