ASHRAE Insights

A common basis for reporting building energy use and comparison of energy performance is available in a new standard from 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 allows different methods of energy analysis to be compared.

This feature of the standard will help facilitate comparison, design and operation improvements and development of building energy performance standards, according to J. Michael MacDonald, Member ASHRAE, chair of the committee that wrote the standard.

“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, which is vital for energy efficiency efforts worldwide, he said.

Past versions of the standard provided a basis for reporting energy use but had limited ability to express or compare performance.

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

MacDonald said 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.