Thornhill Apartments

How does Thornhill Apartments compare with other multifamily (5+ units) buildings in Berkeley?

The latest disclosures cover 202 multifamily (5+ units) buildings in Berkeley, out of 440 buildings citywide. Thornhill Apartments's ENERGY STAR score of 91 compares with an average of 92 across the 156 that report a score; it scores higher than 19% of them and lower than 78%. Its site EUI of 38.1 kBtu/ft² is about 16% above the average of 32.9 kBtu/ft² — it uses more energy per square foot than the typical building in that group.

At 22,604 sq ft, it is about 32% below the average floor area of 33,316 sq ft for those buildings.

How has Thornhill Apartments's energy performance changed over time?

BuildingCensus holds 4 Berkeley disclosures for Thornhill Apartments, covering report years 2022–2025. Its ENERGY STAR score went from 96 in 2022 to 91 in 2025 (-5 points); its best year on file was 2022, at 96. Site EUI moved from 36.3 kBtu/ft² (2022) to 38.1 kBtu/ft² (2025), an 5% increase.

What does an ENERGY STAR score of 91 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 91 means the building performs better than about 91% of its national peers. BuildingCensus bands the score into report-card grades; 91 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 Berkeley, 82% 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. Thornhill Apartments's 38.1 kBtu/ft² across 22,604 sq ft works out to about 0.9 billion Btu (252 MWh-equivalent) in 2025. Its source EUI of 49.3 kBtu/ft² also counts the energy lost generating and delivering that power, which is why it is higher. The disclosure also reports 35,147 kWh of electricity and 7,414 therms of natural gas for the year.

Which law requires Thornhill Apartments to report its energy use?

Thornhill Apartments reports under BESO (BMC Chapter 19.81), the legal basis of Berkeley's Building Emissions Saving Ordinance, which publishes each covered building's annual benchmarking results. The record shown here is the report-year 2025 disclosure (source record berkeley:7780:2025). Berkeley's BESO requires annual benchmarking for commercial and multifamily buildings of 15,000 sq ft or more, with energy assessments at time of listing and every five years for buildings of 25,000 sq ft or more.