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10-116  THIRD PARTY ALTERNATIVE CALCULATION METHOD COMPLIANCE SOFTWARE
(a) Scope. The requirements of this section apply to Alternative Calculation Method (ACM) compliance software used to demonstrate compliance with Part 6 that are developed by third party software developers as specified by Section 10-109(c)3.

(b) Application. Applications for approval of ACM candidate compliance software must include the following materials:

1. Compliance software vendor certification statement that ACM candidate compliance software meets requirements and successfully pass tests specified in the Alternative Calculation Method Reference Manual.
2. Computer runs and summary sheets including, but not limited to, input and output files, files necessary for transferring information to an ECC-provider (if required), and a summary of the compliance results from required computer runs.


Candidate compliance software runs shall be modeled as specified in the Alternative Calculation Method Reference Manual. Vendor of the ACM compliance software may propose alternate tests from those specified in the Alternative Calculation Method Reference Manual when the vendor of the ACM compliance software believes that one or more of the standard tests are not appropriate for the ACM candidate compliance software. Alternative tests will be evaluated by the Energy Commission on a case-by-case basis and will be applied if the proposed tests compare features of the ACM candidate compliance software to the Energy Commission public domain computer program.
3. User manual and changelog describing the functional and analytical capabilities of the ACM candidate compliance software or a complete list of changes to the ACM compliance software. Vendor of the ACM Compliance software shall make a copy of their user manual available to all building departments in California.

The user manual shall provide thorough explanation of the following:

  1. Software capabilities. A section that discusses the program capabilities. Reference may be made to other sections of the user manual for more complete descriptions if appropriate.
  2. Preparing basic input. Description of the basic use of the compliance software for compliance. This section shall include a complete summary of all inputs and commands necessary for compliance.
  3. Checklist for compliance submittal. A checklist of all items that must be included in a compliance submittal to the enforcement agency using the compliance software.
  4. Sample compliance documentation. Complete set of compliance documentation for a sample building. The example shall include all documentation and standard reports that would normally be submitted to an enforcement agency. This example shall be usable as a model for compliance software users and enforcement agencies to demonstrate a proper compliance submittal.
  5. Compliance statement. The following statement shall appear within the first three pages of the user manual, “[Compliance software name] may be used to show compliance with California 2025 Building Energy Efficiency Standards.”
  6. Related publications. References to the Building Energy Efficiency Standards, Residential Compliance Manual, and Nonresidential Compliance Manual and where to find these publications
4. Executable ACM candidate compliance software.
5. Alternative nonresidential energy simulation engine which meets all of the requirements of ASHRAE 140 (2023) including annex A3 and produces results that are accurate to the simulation results of the Energy Commission public domain computer program.
6. Application fee deposit of $1,000 for ACM candidate compliance software that has not been previously approved by the Energy Commission, or for the first approval following an update to the Title 24, Part 6 Building Energy Efficiency Standards.

(c) Approval Process. For approval of an application, the following procedures apply:

1. Submit application. Four copies of an application must be submitted to the Energy Commission.
2. Correspondence with the Energy Commission. Provide additional information or address specific change requests made by the Energy Commission.

The Commission may take the following actions on an application submitted pursuant to this section:

  1.  Approve the application unconditionally;
  2. Restrict approval to specified occupancies, designs, materials, or devices; or
  3. Reject the application.
3. Application fee deposit review. Address additional review costs including additional fees to cover the total costs if greater than the application fee deposit, or refund if the cost of reviewing the application is less than the application fee deposit.
4. Business meeting approval or approval by the Executive Director.
Once approved, the ACM compliance software may be used by users and building officials to demonstrate compliance.

Once approved, the ACM compliance software may be used by users and building officials to demonstrate compliance.

(d) ACM Compliance Software Updates. When revisions are made to ACM compliance software the following procedures apply:

1. Revisions that result in major changes to ACM compliance software..., changes that would affect compliance values, or that match rules established for modeling compliance software documented in the Energy Conservation Manual and Alternative Calculation Method (ACM) Reference Manuals.
  1. Updated ACM compliance software shall comply with the approval process in 10-116(c) and 10-110. The Energy Commission schedule will be based on extent of change to the Energy Commission public domain software and is no shorter than 90 days.
  2. Incorporate changes from the Energy Commission public domain program by directly incorporating the new version of the Energy Commission public domain program or updating alternative nonresidential energy simulation engines to produce results that are accurate to the new version of the Energy Commission public domain program.
  3. Upon approval of updated ACM compliance software, previous versions of the ACM compliance software will expire 90 days after approval of the new version.
2. Revisions that result in minor changes to the ACM compliance software, changes that change user interface or software updates that do not change compliance values.


  1. If the Energy Commission determines that the minor change must be incorporated on a specific schedule, updated ACM compliance software must go through the approval process based on the Energy Commission schedule. The Energy Commission schedule will be based on extent of change to the Energy Commission public domain software and is no shorter than 45 days.
  2. Incorporate changes from the Energy Commission public domain program by directly incorporating the new version of the Energy Commission public domain program or updating alternative nonresidential energy simulation engines to produce results that are accurate to the new version of the Energy Commission public domain program.
  3. Upon approval of updated ACM compliance software, previous versions of the ACM compliance software will expire 60 days after approval of the new version.

Rules established in the Alternative Calculation Method Reference Manual will be updated no more than twice annually in January and July. If ACM compliance software relies on rules that are updated in the Alternative Calculation Method Reference Manual, then the ACM compliance software must be updated. ACM compliance software that is not updated will be decertified.

(e) Expiration. Approval of an ACM compliance software expires and is replaced by approval of a newer version as part of the typical cycle of updating ACM compliance software to account for bug fixes and changes to the Energy Commission public domain program.

(f) Decertification. Decertification is the formal process of withdrawing approval of ACM compliance software as a result of the following:

1. Building Energy Efficiency Standards undergo substantial changes such that the software would fail to confirm compliance with the Building Energy Efficiency Standards.
2. A letter from the vendor of the ACM compliance software requesting that a particular version(s) of ACM compliance software be decertified and describing the reasons why decertification is appropriate.
3. An “initiating party” commences a procedure to decertify an ACM compliance software version(s) according to the following process:
  1. Submit review request. Written communication to the Energy Commission’s Executive director with copies to the Building Standards Office including name of the ACM compliance software and version, nature of error, explanation for why error requires decertification and appropriate data or other information relevant to evaluate error.
  2. Correspondence with interested parties. The Executive Director shall notify and make a copy of the initial written communication available to the vendor of the ACM compliance software and any known interested parties within 30 days of receipt. Interested parties shall have 45 days from the date of the notification provided by the Executive Director to submit comments to the Energy Commission relating to the request.
  3. Correspondence with initiating parties. The Executive Director may request additional information needed to evaluate the identified error within 75 days of receipt of the written communication. The initiating party must respond withing 30 days of the request for additional information.
  4. Workshop. The Executive Director may convene a workshop within 75 days of receipt of the written communication to gather additional information from the initiating party, the vendor of the ACM compliance software, and interested parties. All parties shall have 15 days after a workshop to submit additional information regarding the error.
  5. Determination. Within 90 days of receipt of the written communication, or within 30 days of receipt of complete additional information requested of the initiating party, whichever is later, the Executive Director shall either determine that the ACM compliance need not be decertified or submit to the Commission a written recommendation that the ACM compliance software be decertified.
  6. Decertification. If it is determined that the ACM compliance software be decertified, it shall take effect 60 days later. Within the first 30 days of the 60 day period, the Executive Director shall send out a notice to building officials and interested parties announcing the decertification.

All initiating parties have the burden of proof to establish that the review of ACM compliance software errors should be performed. The decertification process may be terminated at any time by mutual consent of the initiating party and the Executive Director.

The vendor of the ACM compliance software may use the period outline here to update the compliance software, obtain approval by the Energy Commission, and release a revised version that corrects the error initially brough to the attention of the Commission.

 Updated ACM compliance software shall comply with the approval process in 10- 116(c) and 10-110. The Energy Commission schedule will be based on extent of change to the Energy Commission public domain software and is no shorter than 90 days.Updated ACM compliance software shall comply with the approval process in 10- 116(c) and 10-110. The Energy Commission schedule will be based on extent of change to the Energy Commission public domain software and is no shorter than 90 

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