ATLANTA — The American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) is seeking public input through June 18 regarding the revision of an ASHRAE/IES standard addressing retrofit of existing residential and commercial buildings to achieve greater energy efficiency.

Last year, ASHRAE and the Illuminating Engineering Society (IES) announced they were revising ANSI/ASHRAE/IESNA Standard 100-2006, Energy Conservation in Existing Buildings, to provide greater guidance and a more comprehensive approach to the retrofit of existing buildings for increased energy efficiency. The standard was first published in 1981 and, as more attention is being paid to improving energy in today’s current building stock, the need for its requirements has grown.

“Information from the International Energy Agency shows that the building sector is the largest consumer of energy in the U.S., using some 40.3 quadrillion Btu of energy in 2002, which is around 41 percent of total U.S. energy use,” said Rick Hermans, chair of the committee writing the standard. “Compliance with this standard by every building would reduce that energy use by three quarters.”

Proposed changes include criteria for energy use surveys, auditing, and requirements related to implementation and verification. Appendices are included for life cycle cost analysis procedures as well as identification of potential energy conservation measures.

Recognizing the actual occupancy of a building plays a key role in its performance, the standard established the need for development of an energy management plan and an operation and maintenance plan.

“The standard takes advantage of the fact that any building that has been in operation for at least 12 months can quickly determine its performance relative to some benchmark, which is defined in the standard as an energy use intensity target,” said Hermans. “This concept is the new paradigm for new energy conscious design, construction, and operation of buildings.”

The standard provides requirements for the retrofit of existing buildings and addresses major and minor modifications for both residential and commercial buildings, single and multiple activity buildings with variable occupancy periods, and identifies an approach for 53 building types in 16 climate zones/sub-zones.

The revised standard also identifies energy-efficiency requirements for buildings with and without energy targets and provides multiple levels of compliance. For more information, visit

Publication date: 6/4/2012