1611 On Lake Union (Westlake Village)

How does 1611 On Lake Union (Westlake Village) 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. 1611 On Lake Union (Westlake Village)'s ENERGY STAR score of 98 compares with an average of 83 across the 1,652 that report a score; it scores higher than 75% of them and lower than 20%. Its site EUI of 37.6 kBtu/ft² is roughly in line with the average of 34.9 kBtu/ft². Its emissions intensity of 0.9 kgCO₂e/ft² is about 36% above the group average of 0.7 kgCO₂e/ft².

At 66,204 sq ft, it is about 23% below the average floor area of 86,468 sq ft for those buildings. It was built in 2007, 24 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 1611 On Lake Union (Westlake Village)'s energy performance changed over time?

BuildingCensus holds 11 Seattle disclosures for 1611 On Lake Union (Westlake Village), covering report years 2015–2025. Its ENERGY STAR score went from 95 in 2015 to 98 in 2025 (+3 points); its best year on file was 2021, at 99. Site EUI moved from 34.5 kBtu/ft² (2015) to 37.6 kBtu/ft² (2025), an 9% increase. Reported emissions went from 54 tCO₂e to 44 tCO₂e over the same span (down 18%).

What does an ENERGY STAR score of 98 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 98 means the building performs better than about 98% of its national peers. BuildingCensus bands the score into report-card grades; 98 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. 1611 On Lake Union (Westlake Village)'s 37.6 kBtu/ft² across 66,204 sq ft works out to about 2.5 billion Btu (730 MWh-equivalent) in 2025. Its source EUI of 77.3 kBtu/ft² also counts the energy lost generating and delivering that power, which is why it is higher. The disclosure also reports 290,807 kWh of electricity and 7,346 therms of natural gas for the year.

Which law requires 1611 On Lake Union (Westlake Village) to report its energy use?

1611 On Lake Union (Westlake Village) 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:26141:2025). 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.