3101 Western (Formerly Airborne Bldg)

How does 3101 Western (Formerly Airborne Bldg) compare with other office buildings in Seattle?

The latest disclosures cover 497 office buildings in Seattle, out of 3,871 buildings citywide. 3101 Western (Formerly Airborne Bldg)'s ENERGY STAR score of 3 compares with an average of 76 across the 378 that report a score; it scores higher than 1% of them and lower than 98%. Its site EUI of 177.4 kBtu/ft² is about 296% above the average of 44.8 kBtu/ft² — it uses more energy per square foot than the typical building in that group. Its emissions intensity of 1.0 kgCO₂e/ft² is about 47% above the group average of 0.7 kgCO₂e/ft².

At 253,103 sq ft, it is about 29% above the average floor area of 196,452 sq ft for those buildings. It was built in 1984, 19 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 3101 Western (Formerly Airborne Bldg)'s energy performance changed over time?

BuildingCensus holds 11 Seattle disclosures for 3101 Western (Formerly Airborne Bldg), covering report years 2015–2025. Its ENERGY STAR score went from 17 in 2015 to 3 in 2025 (-14 points); its best year on file was 2015, at 17. Site EUI moved from 117.3 kBtu/ft² (2015) to 177.4 kBtu/ft² (2025), an 51% increase. Reported emissions went from 130 tCO₂e to 203 tCO₂e over the same span (up 56%).

What does an ENERGY STAR score of 3 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 3 means the building performs better than about 3% of its national peers. BuildingCensus bands the score into report-card grades; 3 falls in band D — lowest band (1–54). It sits 72 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. 3101 Western (Formerly Airborne Bldg)'s 177.4 kBtu/ft² across 253,103 sq ft works out to about 44.9 billion Btu (13,159 MWh-equivalent) in 2025. Its source EUI of 496.7 kBtu/ft² also counts the energy lost generating and delivering that power, which is why it is higher. The disclosure also reports 10,265,510 kWh of electricity for the year.

Which law requires 3101 Western (Formerly Airborne Bldg) to report its energy use?

3101 Western (Formerly Airborne Bldg) 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:379:2025). 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.