To achieve better energy efficiency, ASHRAE and the Illuminating Engineering Society (IES) have revised a standard, creating a more detailed description of procedures for the retrofit of existing buildings.

The ANSI/ASHRAE/IES Standard 100-2015, Energy Efficiency in Existing Buildings (Standard 100) includes appendices for life-cycle cost analysis procedures and the identification of conservation measures, improving efficiency with an objective benchmark.

“In order to reduce the overall impact of energy used by residential and commercial buildings, the existing building stock must become more efficient,” said Rick Hermans, chair of the Standard 100 committee. “This revision to Standard 100 provides the means to accomplish that goal.”

The standard targets both single and multiple activity buildings with different occupancy periods, looking at 53 building types in 17 climate zones and subzones. As occupancy continues to influence building performance, energy management plans and operation programs are emphasized, along with requirements for ongoing commissioning.

The new revision will benefit buildings undergoing retrofits that don’t apply to other ASHRAE standards.