645 West End Avenue

How does 645 West End Avenue compare with other multifamily housing buildings in New York City?

The latest disclosures cover 33,022 multifamily housing buildings in New York City, out of 48,310 buildings citywide. 645 West End Avenue's ENERGY STAR score of 92 compares with an average of 63 across the 22,829 that report a score; it scores higher than 79% of them and lower than 20%. Its site EUI of 60.1 kBtu/ft² is about 20% below the average of 74.9 kBtu/ft² — it uses less energy per square foot than the typical building in that group. Its emissions intensity of 3.8 kgCO₂e/ft² is about 27% below the group average of 5.2 kgCO₂e/ft².

At 136,062 sq ft, it is about 35% above the average floor area of 100,951 sq ft for those buildings. It was built in 1913, 39 years earlier than the group's average year built (1952). 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.

What does an ENERGY STAR score of 92 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 92 means the building performs better than about 92% of its national peers. BuildingCensus bands the score into report-card grades; 92 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 New York City, 43% 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. 645 West End Avenue's 60.1 kBtu/ft² across 136,062 sq ft works out to about 8.2 billion Btu (2,397 MWh-equivalent) in 2023. Its source EUI of 81.7 kBtu/ft² also counts the energy lost generating and delivering that power, which is why it is higher. The disclosure also reports 424,158 kWh of electricity and 67,313 therms of natural gas for the year.

Which law requires 645 West End Avenue to report its energy use?

645 West End Avenue reports under Local Law 84 (LL84), the legal basis of New York City's Energy and Water Data Disclosure program, which publishes each covered building's annual benchmarking results. The record shown here is the report-year 2023 disclosure (source record nyc:17352842:2023). Under Local Law 97, buildings over 25,000 sq ft face carbon caps with fines of $268 per metric ton of CO₂e over the limit, phasing in from 2024.