The tenth edition building code was filed with the Secretary of State on Tuesday, September 24, 2024, and became effective on October 11, 2024. Concurrency with the 9th Edition of the Building Code has been extended until June 30th, 2025. However, the 9th Edition, being based on IMC 2015 and ASHRAE 15 2013, does not have references or allowances for A2L refrigerants. Projects wishing to use HVAC equipment with A2L refrigerants will need to adhere to the 10th Edition Building Code or attempt to petition BBRS under a 9th Edition compliance.
Two of the eight DXS code change proposals approved by BBRS in July of 2024 have made it into this original version of the 10th Edition Building Code, updating the ASHRAE 15/34 and the UL/CSA 60335-2-40 referenced standards. The remaining six code change proposals (including the one creating the alternate compliance path to IMC 2021 using ASHRAE 15 2022 exclusively) are still making their way through due process. BBRS will be issuing an advisory document explaining that installations abiding by ASHRAE 15 2022 are in compliance with the 10th Edition Building Code.
The 10th Edition CMR 780 Building Code can be found here.