The William Penn Apartments

How does The William Penn Apartments compare with other multifamily housing buildings in Washington, DC?

The latest disclosures cover 1,799 multifamily housing buildings in Washington, DC, out of 6,870 buildings citywide. The William Penn Apartments's ENERGY STAR score of 99 compares with an average of 72 across the 1,618 that report a score; it scores higher than 92% of them and lower than 5%. Its site EUI of 42.9 kBtu/ft² is about 16% below the average of 51.1 kBtu/ft² — it uses less energy per square foot than the typical building in that group. Its emissions intensity of 2.8 kgCO₂e/ft² is about 27% below the group average of 3.8 kgCO₂e/ft².

At 57,004 sq ft, it is about 58% below the average floor area of 136,346 sq ft for those buildings. It was built in 1943, 22 years earlier than the group's average year built (1965). 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 The William Penn Apartments's energy performance changed over time?

BuildingCensus holds 12 Washington, DC disclosures for The William Penn Apartments, covering report years 2013–2024. Its ENERGY STAR score went from 90 in 2014 to 99 in 2024 (+9 points); its best year on file was 2017, at 99. Site EUI moved from 52.1 kBtu/ft² (2013) to 42.9 kBtu/ft² (2024), a 18% decrease. Reported emissions went from 254 tCO₂e to 158 tCO₂e over the same span (down 38%).

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 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. The William Penn Apartments's 42.9 kBtu/ft² across 57,004 sq ft works out to about 2.4 billion Btu (717 MWh-equivalent) in 2024. Its source EUI of 69.8 kBtu/ft² also counts the energy lost generating and delivering that power, which is why it is higher. The disclosure also reports 236,332 kWh of electricity, 16,400 therms of natural gas and 1,863 thousand gallons of water for the year.

Which law requires The William Penn Apartments to report its energy use?

The William Penn Apartments 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:PM4005350:2024). 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.