TECHNICAL FEATURE FIGURE 1 How energy credits fit into energy codes and standards credits as an additional resource for building designers. Additional Savings Above Base Prescriptive; Flexible Choices Standard 90.1 Savings Progress Since its fi rst version in 1975, Standard 90.1 has made signifi cant progress in building energy savings (Figure 2). The last three 90.1 cycles have averaged about 6% to 7% overall energy savings per cycle. The 2022 edition doubled that savings to about 14%, with more than a third of that increase in savings attributable to energy credits. The Core of The Code Equivalent To Base Prescriptive Plus Credits Each credit point represents a savings of 1/10 of 1% of total building energy cost. Load management measures base their cost savings on a typical time-of-use electric price structure adopted by Standing Standards Project Committee (SSPC) 90.1. Compliance requires projects to include energy credit measures that achieve a required energy credit point threshold, which varies by building use type and climate zone. The targeted 5% additional energy cost savings in Standard 90.1-2022 translates into needing 50 credit points for most building types and climate zones. Whole-building performance paths have been adjusted to maintain equivalent energy impact through modifi cations to the Energy Cost Budget in Section 12 and modifi cation of the building performance factors for compliance with Appendix G. Pacifi c Northwest National 0.0% Laboratory (PNNL) has published a detailed technical support document, " 90.1 Energy Credits Analysis Documentation, " 2 that provides additional detail on the development of energy credits for Standard 90.1. PNNL has also developed an " Application Guide " 3 for energy 100 80 60 40 20 1970 History of Energy Credits Energy credits have been adopted in other model building energy codes. Many residential energy codes over the past 20 years have had effi ciency requirements that involved a choice of options. In commercial codes, a choice-based effi ciency concept fi rst appeared in the 2012 International Energy Conservation Code (IECC) as a " select one of three options " approach. This " pick one " approach evolved over the years to include six options in 2015 and eight options in 2018. The 2021 IECC4 expanded to 15 energy credit measures that were assigned points relative to expected savings, allowing measures to be fl exibly selected in a combination that achieves at least 10 credit points, which is equivalent to approximately 2.5% energy savings. A similar credit concept has now been added to Standard 90.1 with a total of 34 measures, and the proposed 2024 IECC is expected to match the expansion FIGURE 2 Progress in Standard 90.1 energy savings (90.1-2022 results are preliminary). Improvement in ASHRAE Standard 90.1 (Year 1975-2022) 12.3% 18.5% 14.0% 4.5% -0.5% 4.6% 7.5% 6.8% 4.7% 14.2% Source: Pacifi c Northwest National Laboratory 1980 1990 Year A U G U S T 2 0 2 3 ashrae.o rg ASHRAE JOURNAL 31 2000 2010 2020 Normalized Energy Use (1975 Use =100)https://ashrae.org/