ATLANTA – A common basis for reporting building energy use and comparison of energy performance is available in a new standard from the American Society of Heating, Refrigerating and Air-Conditioning Engineers Inc. (ASHRAE). ANSI/ASHRAE Standard 105-2007, Standard Methods of Measuring, Expressing and Comparing Building Energy Performance, provides a method of energy performance comparison that can be used for any building, proposed or existing, and that allows different methods of energy analysis to be compared.

According to J. Michael MacDonald, chair of the committee that wrote the standard, this will help facilitate comparison, design and operation improvements, and development of building energy performance standards.

“ASHRAE is working to advance the development and understanding of these advanced building performance comparison methods,” said MacDonald. “This standard provides a framework for assuring access by all interested parties to performance comparison or rating methods that are developed.”

The biggest change to the standard, last published in 1999, is inclusion of building energy performance comparison. Past versions of the standard provided a basis for reporting energy use but had limited ability to express or compare performance.

MacDonald noted that existing standards and building rating systems include requirements related to energy performance comparison.

He also said that the guidance in the standard progresses from energy use index (total annual energy use per square foot) to other indexes, such as energy use per hospital bed, and then to performance comparison frameworks.

The standard identifies key characteristics that users should consider reporting when performance comparisons are of interest, such as the number of workers, weekly hours of operation, and annual cooling and heating degree days.

For more information, visit www.ashrae.org.

Publication date: 09/24/2007