This revised stand-alone Normative Appendix G, "The Performance Rating Method," to Standard 90.1 includes the version of the appendix published in Standard 90.1-2013 (I-P edition) plus addenda k, r, z, aa, ad,bm, and dx. It is being released ahead of the 2016 standard to provide designers, program developers, and software developers an advance look at changes to the Performance Rating Method for the purposes of program and software planning and development.

Users are cautioned that the full 2016 edition of the standard will likely contain additional changes to Appendix G. This document does not constitute the final version.

Changes to the 2013 edition include the following:

• Appendix G can now be used as a path for compliance with the standard.
• The baseline building design is now fixed at a certain level of performance.
• Modelers are now directed to use the default assemblies in Appendix A for baseline opaque envelope assemblies.
• The hierarchy of the decision-making process for selecting baseline HVAC systems is reestablished.
• New detail is provided on the simulation of baseline building heat pumps.
• New direction is provided regarding when it's appropriate to model a heating-only system in Appendix G.
• Clarification is provided for when baseline HVAC systems should be modeled with preheat coils.
• Changes are made to the baseline lighting power allowances in Appendix G.