Code Information

Building Codes

The City of Missoula has adopted the following codes effective March 7, 2020.

  • 2018 International Building Code (IBC)
  • 2018 International Energy Conservation Code (IECC)
  • 2018 International Existing Building Code (IEBC)
  • 2018 International Fuel Gas Code (IFGC)
  • 2018 International Mechanical Code (IMC)
  • 2018 International Residential Code (IRC)
  • 2017 National Electrical Code (NEC)
  • 2018 Uniform Plumbing Code (UPC)
  • ICC A117.1 – Accessibility, 2009 Edition
  • NFPA 99c, Standard on Gas and Vacuum Systems (med gas), 2018 Edition

Code Change Documents

The City has recently adopted the State mandated code updates. Below are documents addressing the significant changes from the previously adopted codes to the current adopted codes. 

Note: These documents are a summary and do not include all code changes or modifications. Readers are advised to research and verify any code changes and requirements related to their projects. These documents are not to be used as a replacement of, or modification to, officially adopted code documents.

Snow Load

The snow load for the City of Missoula is 30 pounds per square foot and the wind load is roughly 90 miles per hour. See IBC 1609 or IRC 301.2 for an exact number.

More Information

To purchase code books, visit the International Code Council.

Building Residential Occupancies on Hillsides or Slopes

R401.3 Drainage - Surface drainage shall be diverted to a storm sewer conveyance or other approved point of collection so as to not create a hazard. Lots shall be graded so as to drain surface water away from foundation walls. The grade away from foundation walls shall fall a minimum of 6" (152 mm) within the first 10’ (3,048 mm). One exception is where lot lines, walls, slopes, or other physical barriers prohibit 6" (152 mm) of fall within 10’ (3,048 mm), drains or swales shall be provided to ensure drainage away from the structure.