Proposed ASHRAE Energy Simulation Standard Open For Public Review

ATLANTA – A draft standard that describes a methodology to apply building energy modeling to the design process is open for industry input.

 ASHRAE Standard 209P, Energy Simulation Aided Design for Buildings Except Low-Rise Residential Buildings, defines minimum requirements for providing energy design assistance using building energy simulation and analysis.

The proposed standard is open for public comment until May 9, 2016. To comment or learn more, visit

“ASHRAE recognizes that building energy simulation is most useful when it can inform the design process to reduce energy use,” Jason Glazer, chair of the Standard 209P committee, said. “The standard was created to advance the use of timely building energy modeling to quantify how design decisions can affect building energy use when those design decisions are being made.”

While earlier draft versions of the proposed standard incorporated energy modeling into the typical design process divisions of schematic design, design development, etc., the committee realized that many tasks, data and goals of each modeling effort, or cycle, were similar enough to create a “generic modeling cycle.” The draft standard was rewritten to incorporate a generic modeling cycle that is augmented with additional directions to create several specific modeling cycles that are incorporated into the typical design process.

Standard 209P defines seven design phase modeling cycles with specific modeling goals that are defined and coordinated with the typical design process, and three modeling cycles are defined that apply during construction and operation of the buildings. Each modeling cycle is an extension of a general modeling cycle that can be applied any time during the design process that energy modeling is needed to inform design decisions. In addition, a post-occupancy comparison is included to help owners and modelers understand how modeled results compare actual energy performance and inform assumptions in future modeling projects.

“The minimum requirements of the standard can be met by utilizing building energy modeling to evaluate load reduction measures early in the design process, as well as one additional design phase modeling cycle,” Glazer said. “Other modeling cycles are included for organizations that wish to adopt more robust energy modeling requirements.”

While the standard can be applied with any design process, it is anticipated to be most effective when included in an integrative design process. It is expected the 209P will be adopted by organizations that certify high performance buildings as well as utilities and agencies that provide incentives for low energy buildings, and used by building owners and architects seeking a uniform way to specify a scope of work for building energy modeling.

ASHRAE, founded in 1894, is a global society advancing human well-being through sustainable technology for the built environment. The Society and its more than 55,000 members worldwide focus on building systems, energy efficiency, indoor air quality, refrigeration and sustainability. Through research, standards writing, publishing, certification and continuing education, ASHRAE shapes tomorrow’s built environment today. More information can be found at