Interurban Building (Old Smith Tower Annex Building)

How does Interurban Building (Old Smith Tower Annex Building) compare with other office buildings in Seattle?

The latest disclosures cover 497 office buildings in Seattle, out of 3,871 buildings citywide. Interurban Building (Old Smith Tower Annex Building)'s ENERGY STAR score of 86 compares with an average of 76 across the 378 that report a score; it scores higher than 56% of them and lower than 40%. Its site EUI of 33.5 kBtu/ft² is about 25% 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 0.2 kgCO₂e/ft² is about 73% below the group average of 0.7 kgCO₂e/ft².

At 75,496 sq ft, it is about 62% below the average floor area of 196,452 sq ft for those buildings. It was built in 1900, 65 years earlier 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 Interurban Building (Old Smith Tower Annex Building)'s energy performance changed over time?

BuildingCensus holds 11 Seattle disclosures for Interurban Building (Old Smith Tower Annex Building), covering report years 2015–2025. Its ENERGY STAR score went from 85 in 2024 to 86 in 2025 (+1 points). Site EUI moved from 55.6 kBtu/ft² (2015) to 33.5 kBtu/ft² (2025), a 40% decrease. Reported emissions went from 19 tCO₂e to 15 tCO₂e over the same span (down 25%).

What does an ENERGY STAR score of 86 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 86 means the building performs better than about 86% of its national peers. BuildingCensus bands the score into report-card grades; 86 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. Interurban Building (Old Smith Tower Annex Building)'s 33.5 kBtu/ft² across 75,496 sq ft works out to about 2.5 billion Btu (741 MWh-equivalent) in 2025. Its source EUI of 93.8 kBtu/ft² also counts the energy lost generating and delivering that power, which is why it is higher. The disclosure also reports 741,581 kWh of electricity and 1 therms of natural gas for the year.

Which law requires Interurban Building (Old Smith Tower Annex Building) to report its energy use?

Interurban Building (Old Smith Tower Annex 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:614:2025). 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.