In the New York City commercial real estate market, large building operators have a dramatic impact on buildings' energy performance. With identical technology and systems in two different buildings with similar space uses, the efficiently operated building can run at 20-30% lower energy intensity. A recent initiative has assembled energy consumption benchmark data and other characteristics on a large sample of buildings owned or managed by leading New York area firms, which has provided a forum for sharing and discussing best practices toward continuous improvement in building energy performance.

A variety of lessons have been learned through the effort. Confidentiality of data is a real challenge, as is ensuring that all meters/energy use is captured for benchmarking. A variety of sometimes hard to detect changes, such as building occupancy patterns, vacancy of spaces, and addition of energy-intensive equipment, often have far greater impact on the energy performance than any energy-efficiency changes. Analysis of these drivers is important for understanding whether energy performance is improving or getting worse.

A valuable set of building performance data has been collected covering over 90 million square feet. Analysis of this data yields important insights into the impact of building operations, age, occupancy, equipment, and efficiency measures on overall energy consumption patterns. This paper will analyze the data and present the mix of buildings' physical and operational characteristics, their impact on energy consumption, and opportunities for further enhancements of energy performance across a range of larger commercial buildings in New York City.