Adopted Codes & Design Criteria

Adopted Codes - Effective January 1, 2021

• 2018 International Building Code, with amendments 
• 2018 International Residential Code (parts I, II, III, and IX), with Idaho amendments, collectively named the Idaho Residential Code (2020 Edition)
• 2018 International Energy Conservation Code, with amendments, collectively named the Idaho Energy Conservation Code (2020 Edition) 
• 2018 International Existing Building Code

*Note - Idaho amendments to the IRC contain a typo under 07.03.01.004.02.q. Table R403 became Table R403.4 in the final printing of the 2018 IRC

**Note - The reference to 2020 Edition is an identifier to the legislative session in which the amendments were adopted.  Amendments can be made in any legislative cycle regardless of the code cycle.

Electrical Codes

• 2017 National Electrical Code, with amendments (NEC)

Mechanical Codes

• 2018 International Mechanical Code (IMC) 
• 2018 International Fuel & Gas Code (IFGC) 
• 2018 International Residential Code Parts V & VI

Plumbing Codes

• 2017 Idaho State Plumbing Code (ISPC) based on the 2015 Uniform Plumbing Code. 
• Link to View Plumbing Code Online

Fire Code (administered by the Idaho Fire Marshall)

• 2018 International Fire Code (IFC)
• Link to State Fire Marshall's Office

​General Design Guidelines 

If the information is not found below, refer to the adopted codes stated above for proper design methods to meet minimum compliance.

• Snow Load - Ground snow loads = 20 psf and also determined by section 7, of ASCE 7, however the design roof load shall not be less than a uniform snow load of 25 psf
• Floor Loads - live load 40 psf, dead load 20 psf / total 60 psf or ASCE 7, Table 4-1 for conditions that would require a greater load.
• Lateral Loads - ASCE 7 and adopted IBC. Geotechnical report required
• Wind - 115 mph risk occupancy II or less; 120 mph for risk occupancy III, or greater
• Soil Properties - Geotechnical report required for structures in seismic design
• Frost line - 24 inches
• Weathering - Severe
• Exposure - C
• Termite - Slight to Moderate
• Decay - Slight to None
• Winter Design Temperature - 10 degrees (F).
• Annual Mean Temperature - 51.1
• Floodplain Ordinance - FIRM 2003 in effect (flood insurance rate maps)
• Air Freezing Index - 294 (National Climatic Data Center)
• Ice Barrier Underlayment Required? - No