Building Energy Code

Much of the information presented in this summary is drawn from the U.S. Department of Energy’s (DOE) Building Energy Codes Program and the Building Codes Assistance Project (BCAP). For more detailed information about building energy codes, visit the DOE and BCAP websites.

The energy codes are reviewed on a three-year cycle corresponding to the adoption of new versions of the International Code Conference (ICC) Uniform Codes. Proposed changes are submitted to the Building Codes Bureau. In fall 2014, Montana adopted the 2012 IECC with state amendments. If an approved local government code enforcement program does not exist, the State Building Codes Bureau enforces the applicable codes on commercial buildings and residential buildings with five or more dwellings. On June 11, 2022, Montana adopted the 2021 IECC with amendments for residential buildings and the 2021 IECC and ASHRAE 90.1-2019 without amendments for commercial buildings.

H.B. 420, passed in April 2009, allows local city and county jurisdictions with a building code enforcement program to adopt energy conservation standards that are more stringent than the state code. These energy conservation standards must be voluntary and linked to an incentive program for energy conservation, where only buildings receiving an incentive will be required to meet the more stringent standard.

When required by the building official, plans and specifications must be submitted. The building official may also require that plans and specifications be prepared by a licensed architect or engineer. A registered architect or engineer may prepare all energy compliance submissions or COMcheck and REScheck will also be acceptable means of showing compliance.