One Mass Ave

How does One Mass Ave compare with other office buildings in Washington, DC?

The latest disclosures cover 899 office buildings in Washington, DC, out of 6,870 buildings citywide. One Mass Ave's ENERGY STAR score of 77 compares with an average of 70 across the 774 that report a score; it scores higher than 53% of them and lower than 44%. Its site EUI of 44.8 kBtu/ft² is about 19% below the average of 55.6 kBtu/ft² — it uses less energy per square foot than the typical building in that group. Its emissions intensity of 3.9 kgCO₂e/ft² is about 21% below the group average of 5.0 kgCO₂e/ft².

At 195,276 sq ft, it is roughly in line with the average floor area of 216,135 sq ft for those buildings. It was built in 1990, 16 years later than the group's average year built (1974). 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 One Mass Ave's energy performance changed over time?

BuildingCensus holds 13 Washington, DC disclosures for One Mass Ave, covering report years 2012–2024. Its ENERGY STAR score went from 80 in 2012 to 77 in 2024 (-3 points); its best year on file was 2016, at 93. Site EUI moved from 64.3 kBtu/ft² (2012) to 44.8 kBtu/ft² (2024), a 30% decrease. Reported emissions went from 1,777 tCO₂e to 768 tCO₂e over the same span (down 57%).

What does an ENERGY STAR score of 77 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 77 means the building performs better than about 77% of its national peers. BuildingCensus bands the score into report-card grades; 77 falls in band B — above median (70–84). 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 Washington, DC, 47% 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. One Mass Ave's 44.8 kBtu/ft² across 195,276 sq ft works out to about 8.7 billion Btu (2,564 MWh-equivalent) in 2024. Its source EUI of 125.5 kBtu/ft² also counts the energy lost generating and delivering that power, which is why it is higher. The disclosure also reports 2,564,390 kWh of electricity, 0 therms of natural gas and 2,788 thousand gallons of water for the year.

Which law requires One Mass Ave to report its energy use?

One Mass Ave reports under the Clean and Affordable Energy Act / BEPS, the legal basis of Washington, DC's Building Energy Benchmarking program, which publishes each covered building's annual benchmarking results. The record shown here is the report-year 2024 disclosure (source record dc:PM1852852:2024). DC's Building Energy Performance Standards (BEPS) require buildings below the performance standard to improve over compliance cycles (the first ends December 31, 2026; later cycles run five years), with penalties for buildings that fail to meet their pathway.