Union - Slu

How does Union - Slu compare with other multifamily housing buildings in Seattle?

The latest disclosures cover 1,971 multifamily housing buildings in Seattle, out of 3,871 buildings citywide. Union - Slu's ENERGY STAR score of 95 compares with an average of 83 across the 1,652 that report a score; it scores higher than 61% of them and lower than 35%. Its site EUI of 38.8 kBtu/ft² is about 11% above the average of 34.9 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 41% above the group average of 0.7 kgCO₂e/ft².

At 334,785 sq ft, it is about 287% above the average floor area of 86,468 sq ft for those buildings. It was built in 2012, 29 years later than the group's average year built (1983). Across all 24 jurisdictions BuildingCensus covers, the 59,945 multifamily housing buildings average an ENERGY STAR score of 70 and a site EUI of 59.0 kBtu/ft².

How has Union - Slu's energy performance changed over time?

BuildingCensus holds 11 Seattle disclosures for Union - Slu, covering report years 2015–2025. Its ENERGY STAR score was 95 in both 2015 and 2025. Site EUI moved from 37.6 kBtu/ft² (2015) to 38.8 kBtu/ft² (2025), an 3% increase. Reported emissions went from 272 tCO₂e to 195 tCO₂e over the same span (down 28%).

What does an ENERGY STAR score of 95 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 95 means the building performs better than about 95% of its national peers. BuildingCensus bands the score into report-card grades; 95 falls in band A — high performer (85–100). Scores of 75 or higher meet the threshold for ENERGY STAR certification; certification itself is a separate, verified application that the disclosure does not record. 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. Union - Slu's 38.8 kBtu/ft² across 334,785 sq ft works out to about 13 billion Btu (3,807 MWh-equivalent) in 2025. Its source EUI of 78.9 kBtu/ft² also counts the energy lost generating and delivering that power, which is why it is higher. The disclosure also reports 1,265,385 kWh of electricity and 33,453 therms of natural gas for the year.

Which law requires Union - Slu to report its energy use?

Union - Slu 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:49730:2025). 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.