Major Shift in Building Codes Rewards Innovative Building Science
Building designers, owners, and operators are in line to benefit from the most significant change in performance-based energy code compliance to happen in more than 25 years. Approved by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers' (ASHRAE) Standard 90.1 committee in April of 2015, the recent "Addendum bm" to Standard 90.1 provides a fixed and independent baseline for energy-saving building design improvements, resulting in more flexibility to unlock future energy savings potential.
In support of the Department of Energy's Office of Energy Efficiency and Renewable Energy (EERE), PNNL was instrumental in creating this shift through their leadership of the Building Energy Codes Program for the EERE Buildings Technologies Office. In response to their challenge to improve the energy code by 50% compared to the 2004 reference year, PNNL began working on this new approach in 2011. From concept to proposal, and with three rounds of public review, PNNL shepherded this change through the arduous American National Standards Institute consensus process.
The change came only after performing thousands of parametric energy simulations, working to establish consensus from the stakeholders on the ASHRAE committee, and addressing comments submitted by external stakeholders during each round of public review.
Fixed AND Independent
The baseline is fixed. As the code improves with each change cycle, the baseline remains at the same performance level and only the target for compliance changes. This allows the same "minimum code compliance" baseline to determine compliance with above-code programs (such as Leadership in Energy & Environmental Design or Energy Policy Act tax incentives) by simply setting a higher target. As each successive code is released, the performance target relative to the fixed baseline changes, resulting in a longer "shelf-life" for the performance rules. This will increase simulation accuracy, decrease project costs, and encourage the development of software programs to aid in the design process.
Addendum bm's baseline is also independent, meaning more design strategies supporting energy savings will be recognized and given credit. It provides incentives for good design choices, such as optimizing building orientation and window area, using an appropriate mechanical system, and installing "right-sized" HVAC equipment. Prior to this change, such design strategies were held constant between a proposed building and a comparative baseline and were not recognized by performance based codes.
PNNL Research Team: Michael Rosenberg, Reid Hart, Jian Zhang, Rahul Athalye, and Eric Richman