2022 Alternative Calculation Method Approval Manual: for the 2022 Building Energy Efficiency Standards Title 24, Part 6, and Associated Administrative Regulations in Part 1

This manual explains the requirements for approval of Alternative Calculation Methods (ACMs), which include compliance software. Compliance software is used to demonstrate compliance with the performance approach to the 2022 Building Energy Efficiency Standards for Residential and Nonresidential Buildings (Standards). The residential requirements of this document apply to buildings covered by the low-rise residential provisions of the Standards. All building types other than low-rise residential that are within the scope of the Standards are covered by the nonresidential requirements of this document.

The approval procedure for ACM compliance software is one of self-testing and self-certification by the software vendor. The vendor conducts the specified tests, evaluates the results and certifies in writing that the compliance software passes the tests. The California Energy Commission performs spot checks and can require additional tests to verify that the proposed compliance software is suitable for compliance purposes. The vendor is required to develop a user manual explaining how to use the program to show compliance with the Standards. The user manual must include a tutorial, user guidance for each program input, and an index. The manual is checked by the Energy Commission for accuracy and ease of use.

Open source compliance software developed by the Energy Commission, called the Compliance Manager in this document, is made available at no cost to potential compliance software vendors, and is created and approved by the Energy Commission following the specifications of this Manual. The ACM tests submitted by the vendor either confirm and document that the Compliance Manager is successfully integrated into the vendor software, or demonstrate that the vendor software accurately achieves the same results as the Energy Commission’s software.

Section 1 presents the general requirements for compliance software, and for applications for approval of third-party modeling software.

Section 2 provides the specifications and requirements that apply to the Compliance Manager in establishing the standard design energy use of residential and nonresidential buildings. The Residential and Nonresidential ACM Reference Manuals required by Section 2.4 are documents that are developed and maintained by the Energy Commission to document in greater detail the specific building performance modeling calculations implemented in the Compliance Manager software and used to model building performance. These reference manuals are approved by the Energy Commission and updated as necessary to resolve issues identified during implementation.

Section 3 describes the required content of the user manuals provided by software vendors for their compliance products. The certification tests that compliance software must pass in order to receive approval are documented in detail in Appendix A for low-rise residential buildings and Appendix B for nonresidential buildings.