The following are building codes that have been adopted by the City of Billings:
- International Building Code, 2018 Edition
- International Energy Conservation Code, 2012 Edition
- International Existing Building Code, 2018 Edition
- International Fuel Gas Code, 2018 Edition
- International Mechanical Code, 2018 Edition
- International Residential Code, 2018 Edition
- National Electrical Code, 2017 Edition
- NFPA 99c, Standard on Gas and Vacuum Systems (med gas), 2018 Edition
- Uniform Plumbing Code, 2018 Edition
- International Swimming Pool & Spa Code, 2018 Edition
