ASHRAE/IES has published a new energy standard that substantially changes requirements related to building envelope, lighting, mechanical systems and the energy cost budget.

“While many things have changed since the first version of Standard 90 was published in 1975, the need to reduce building energy use and cost has not,” says Steve Skalko, chair of the committee that wrote the 2013 standard. “This standard represents many advances over the 2010 standard, as we worked toward our goal of making the standard 40 to 50 per cent more stringent than the 2004 standard.”

The ANSI/ASHRAE/IES Standard 90.1-2013, Energy Standard for Buildings Except Lowrise Residential Buildings, incorporates 110 changes that were made through the public review process.

Lighting presented challenges for the committee that established the 2013 standards. According to Rita Harrold, director of technology for the Illuminating Engineering Society of North America, interior lighting power densities (LPD) were re-evaluated and lowered. However, there are ongoing concerns about maintaining the quality of lighting installations for occupant satisfaction and comfort while achieving energy savings.

“The focus in the 2013 standard, therefore, was not just on lowering LPDs but on finding ways to achieve savings by adding more controls and daylighting requirements as well as including lighting limits for exterior applications based on jurisdictional zoning,” says Harrold.

The most significant changes to lighting include improvements to daylighting and daylighting controls, space-by-space LPD limits, thresholds for top lighting and revised control requirements.