Addendum 66f amends the MINHERS Chapter 3 to add criteria for the calculation and labeling of the CO2e Index. The addendum identifies data and establishes criteria for calculating and reporting the CO2e Index necessary for software providers to revise their HERS Index rating software. Development of the CO2e Index rating utilizes current Minimum Rated Features and does not require additional data to be collected by raters. An interim version of Addendum 66, (66i), was adopted by RESNET and is currently in effect to allow software providers to begin revising their software. The final version of Addendum 66, (66f), provides additional clarifications and other minor changes to 66i. Reporting the CO2e Index will be Voluntary until January 1, 2023. Comments will be accepted only on changes to draft PDS-02 shown by text as strikeout and underline in red print. Other text shown in strikeout/underline were submitted for public review in drafts PDS-01 and PDS-02 and are no longer open for comment. To review the draft Addendum click on Draft PDS-03 MINHERS Addendum 66f, CO2e Index To submit your comments, click on RESNET Amendment Comment Online Form for Draft PDS-03 MINHERS Addendum 66f, CO2e Index Comments are posted in real-time and you will be able to review comments by clicking on Comments Submitted on Draft PDS-03 MINHERS Addendum 66f, CO2e Index The public comment period will begin August 12, 2022, and end September 11, 2022.