Sixth & Wall Building (521 Wall St)
Mixed Use Property in Seattle, WA · 521 WALL ST · 98121
At a glance
Sixth & Wall Building (521 Wall St) is a 192,630-square-foot mixed use property building at 521 WALL ST in Seattle, Washington, built in 1947. In its 2025 Seattle benchmarking disclosure it reported a site energy-use intensity of 35.0 kBtu/ft² and 42 tCO₂e of greenhouse-gas emissions.
Seattle Energy Benchmarking Ordinance (SMC 22.920) · reporting year 2025
Benchmarking record
| Field | Value |
|---|---|
| ENERGY STAR score | — |
| Site EUI | 35.0 kBtu/ft² |
| Source EUI | 95.2 kBtu/ft² |
| GHG emissions | 42 tCO₂e |
| GHG intensity | 0.3 kgCO₂e/ft² |
| Electricity | 1,458,049 kWh |
| Natural gas | 2,516 therms |
| Gross floor area | 192,630 sq ft |
| Source record | seattle:377:2025 |
The disclosure history
Year over year
| Year | Score | Δ | Site EUI | GHG emissions |
|---|---|---|---|---|
| 2025latest | — | 35.0 kBtu/ft² | 42 tCO₂e | |
| 2024 | — | 41.8 kBtu/ft² | 54 tCO₂e | |
| 2023 | — | 42.0 kBtu/ft² | 54 tCO₂e | |
| 2022 | — | 42.3 kBtu/ft² | 53 tCO₂e | |
| 2021 | — | 37.1 kBtu/ft² | 42 tCO₂e | |
| 2020 | 91 | +7 | 34.9 kBtu/ft² | 41 tCO₂e |
| 2019 | 84 | -2 | 39.0 kBtu/ft² | 48 tCO₂e |
| 2018 | 86 | +8 | 36.5 kBtu/ft² | 44 tCO₂e |
| 2017 | 78 | -16 | 40.5 kBtu/ft² | 56 tCO₂e |
| 2016 | 94 | 36.7 kBtu/ft² | 40 tCO₂e | |
| 2015 | — | 37.1 kBtu/ft² | 31 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
- 521 WALL ST
- City
- Seattle
- State
- Washington
- ZIP
- 98121
- Coordinates
- 47.61734, -122.34434
Within ~1 km
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See also: most efficient in Seattle · biggest emitters
How does Sixth & Wall Building (521 Wall St) compare with other mixed use property buildings in Seattle?
The latest disclosures cover 157 mixed use property buildings in Seattle, out of 3,871 buildings citywide. Its site EUI of 35.0 kBtu/ft² is about half of the average of 68.7 kBtu/ft² — it uses less energy per square foot than the typical building in that group. Its emissions intensity of 0.3 kgCO₂e/ft² is about 80% below the group average of 1.4 kgCO₂e/ft².
At 192,630 sq ft, it is about 16% above the average floor area of 165,352 sq ft for those buildings. It was built in 1947, 21 years earlier than the group's average year built (1968). Across all 24 jurisdictions BuildingCensus covers, the 1,212 mixed use property buildings average an ENERGY STAR score of 69 and a site EUI of 79.8 kBtu/ft².
How has Sixth & Wall Building (521 Wall St)'s energy performance changed over time?
BuildingCensus holds 11 Seattle disclosures for Sixth & Wall Building (521 Wall St), covering report years 2015–2025. Its ENERGY STAR score went from 94 in 2016 to 91 in 2020 (-3 points); its best year on file was 2016, at 94. Site EUI moved from 37.1 kBtu/ft² (2015) to 35.0 kBtu/ft² (2025), a 6% decrease. Reported emissions went from 31 tCO₂e to 42 tCO₂e over the same span (up 37%).
What does a site EUI of 35.0 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. Sixth & Wall Building (521 Wall St)'s 35.0 kBtu/ft² across 192,630 sq ft works out to about 6.7 billion Btu (1,976 MWh-equivalent) in 2025. Its source EUI of 95.2 kBtu/ft² also counts the energy lost generating and delivering that power, which is why it is higher. The disclosure also reports 1,458,049 kWh of electricity and 2,516 therms of natural gas for the year.
Which law requires Sixth & Wall Building (521 Wall St) to report its energy use?
Sixth & Wall Building (521 Wall St) 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:377:2025). 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 mixed use property buildings in Seattle
- Elliott Park Building· 190,000 sq ft · EUI 157.2 kBtu/ft²
- Sodo Urban Works· 188,681 sq ft · EUI 153.0 kBtu/ft²
- Commons At Ballard· 178,578 sq ft · score 96 (A)
- Capco Plaza (Altamira + Qfc Etc.)· 177,417 sq ft · score 93 (A)
- 500 Fairview Research Center Ii· 167,201 sq ft · EUI 128.6 kBtu/ft²
- CITY WATCH APTS· 163,699 sq ft · score 85 (A)
- Mixed Use Property buildings in Seattle· 157 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 Sixth & Wall Building (521 Wall St)'s energy grade?
Sixth & Wall Building (521 Wall St) did not report an ENERGY STAR score in its 2025 disclosure, but its site energy-use intensity was 35.0 kBtu/ft².
How much energy does Sixth & Wall Building (521 Wall St) use?
Its 2025 site energy-use intensity was 35.0 kBtu/ft² (95.2 kBtu/ft² source) across 192,630 sq ft, including 1,458,049 kWh of electricity and 2,516 therms of natural gas.
What are Sixth & Wall Building (521 Wall St)'s carbon emissions?
Sixth & Wall Building (521 Wall St) reported 42 tCO₂e of greenhouse-gas emissions (0.3 kgCO₂e/ft²) for 2025.
Where is Sixth & Wall Building (521 Wall St)?
Sixth & Wall Building (521 Wall St) is at 521 WALL ST, in Seattle, Washington 98121. Its coordinates are 47.61734, -122.34434 (latitude, longitude), as published in the Building Energy Benchmarking file.
How big is Sixth & Wall Building (521 Wall St) and when was it built?
Sixth & Wall Building (521 Wall St) has 192,630 sq ft of gross floor area, as reported in its 2025 disclosure. The disclosure lists 1947 as its year built. It is classed as mixed use property.
Is Sixth & Wall Building (521 Wall St) 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, “Sixth & Wall Building (521 Wall St), Seattle, Washington — 2025 benchmarking disclosure”, https://buildingcensus.com/buildings/seattle/sixth-wall-building-521-wall-st-b37148ef (data as of October 2, 2026).