Westlake Steps & Marina Slu

How does Westlake Steps & Marina 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. Westlake Steps & Marina Slu's ENERGY STAR score of 99 compares with an average of 83 across the 1,652 that report a score; it scores higher than 80% of them and lower than 12%. Its site EUI of 31.0 kBtu/ft² is about 11% below the average of 34.9 kBtu/ft² — it uses less energy per square foot than the typical building in that group. Its emissions intensity of 0.7 kgCO₂e/ft² is roughly in line with the group average of 0.7 kgCO₂e/ft².

At 393,641 sq ft, it is about 355% above the average floor area of 86,468 sq ft for those buildings. It was built in 2016, 33 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 Westlake Steps & Marina Slu's energy performance changed over time?

BuildingCensus holds 8 Seattle disclosures for Westlake Steps & Marina Slu, covering report years 2018–2025. Its ENERGY STAR score was 99 in both 2018 and 2025. Site EUI moved from 21.1 kBtu/ft² (2018) to 31.0 kBtu/ft² (2025), an 47% increase. Reported emissions went from 198 tCO₂e to 228 tCO₂e over the same span (up 15%).

What does an ENERGY STAR score of 99 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 99 means the building performs better than about 99% of its national peers. BuildingCensus bands the score into report-card grades; 99 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. Westlake Steps & Marina Slu's 31.0 kBtu/ft² across 393,641 sq ft works out to about 12.2 billion Btu (3,576 MWh-equivalent) in 2025. Its source EUI of 65.9 kBtu/ft² also counts the energy lost generating and delivering that power, which is why it is higher. The disclosure also reports 1,757,051 kWh of electricity and 37,607 therms of natural gas for the year.

Which law requires Westlake Steps & Marina Slu to report its energy use?

Westlake Steps & Marina 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:50324:2025). 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.