400 Mercer Street Office Building

How does 400 Mercer Street Office Building compare with other office buildings in Seattle?

The latest disclosures cover 497 office buildings in Seattle, out of 3,871 buildings citywide. 400 Mercer Street Office Building's ENERGY STAR score of 64 compares with an average of 76 across the 378 that report a score; it scores higher than 20% of them and lower than 80%. Its site EUI of 37.3 kBtu/ft² is about 17% below 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 0.5 kgCO₂e/ft² is about 27% below the group average of 0.7 kgCO₂e/ft².

At 80,019 sq ft, it is about 59% below the average floor area of 196,452 sq ft for those buildings. It was built in 1987, 22 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 400 Mercer Street Office Building's energy performance changed over time?

BuildingCensus holds 11 Seattle disclosures for 400 Mercer Street Office Building, covering report years 2015–2025. Its ENERGY STAR score went from 95 in 2015 to 64 in 2025 (-31 points); its best year on file was 2017, at 100. Site EUI moved from 34.5 kBtu/ft² (2015) to 37.3 kBtu/ft² (2025), an 8% increase. Reported emissions went from 40 tCO₂e to 32 tCO₂e over the same span (down 20%).

What does an ENERGY STAR score of 64 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 64 means the building performs better than about 64% of its national peers. BuildingCensus bands the score into report-card grades; 64 falls in band C — below median (55–69). It sits 11 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. 400 Mercer Street Office Building's 37.3 kBtu/ft² across 80,019 sq ft works out to about 3 billion Btu (875 MWh-equivalent) in 2025. Its source EUI of 92.5 kBtu/ft² also counts the energy lost generating and delivering that power, which is why it is higher. The disclosure also reports 567,362 kWh of electricity and 4,392 therms of natural gas for the year.

Which law requires 400 Mercer Street Office Building to report its energy use?

400 Mercer Street Office 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 2025 disclosure (source record seattle:549:2025). 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.