507 Northgate

How does 507 Northgate compare with other mixed use property buildings in Seattle?

The latest disclosures cover 157 mixed use property buildings in Seattle, out of 3,871 buildings citywide. 507 Northgate's ENERGY STAR score of 21 compares with an average of 74 across the 29 that report a score; it scores higher than 7% of them and lower than 90%. Its site EUI of 59.2 kBtu/ft² is about 14% below the average of 68.7 kBtu/ft² — it uses less energy per square foot than the typical building in that group. Its emissions intensity of 1.0 kgCO₂e/ft² is about 31% below the group average of 1.4 kgCO₂e/ft².

At 295,410 sq ft, it is about 79% above the average floor area of 165,352 sq ft for those buildings. It was built in 2008, 40 years later than the group's average year built (1968). Across all 24 jurisdictions BuildingCensus covers, the 1,212 mixed use property buildings average an ENERGY STAR score of 69 and a site EUI of 79.8 kBtu/ft².

How has 507 Northgate's energy performance changed over time?

BuildingCensus holds 11 Seattle disclosures for 507 Northgate, covering report years 2015–2025. Its ENERGY STAR score went from 18 in 2018 to 21 in 2025 (+3 points); its best year on file was 2022, at 37. Site EUI moved from 72.8 kBtu/ft² (2015) to 59.2 kBtu/ft² (2025), a 19% decrease. Reported emissions went from 212 tCO₂e to 164 tCO₂e over the same span (down 23%).

What does an ENERGY STAR score of 21 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 21 means the building performs better than about 21% of its national peers. BuildingCensus bands the score into report-card grades; 21 falls in band D — lowest band (1–54). It sits 54 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. 507 Northgate's 59.2 kBtu/ft² across 295,410 sq ft works out to about 17.5 billion Btu (5,125 MWh-equivalent) in 2025. Its source EUI of 141.0 kBtu/ft² also counts the energy lost generating and delivering that power, which is why it is higher. The disclosure also reports 2,252,082 kWh of electricity and 24,187 therms of natural gas for the year.

Which law requires 507 Northgate to report its energy use?

507 Northgate 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:21951:2025). 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.