Design Criteria: Residential

Effective January, 1 2021

2018 International Residential Code, Parts I-VI and IX, appendices A, B and G (with State amendments).

2018 International Energy Conservation Code (with Idaho State amendments)

2017 National Electrical Code (with State amendments)

Wind Speed: 115 mph gust velocity
Wind Exposure: “B” (“C” in some areas)
Seismic Design Category: “B” (IRC Structures Only-See Commercial Design Criteria for IBC)
Presumed Soil Bearing Pressure: 1500 psf without soils investigation
Frost Depth: 24 inches
Climate Zone: 5B
Snow load: Ground snow load 15 psf. Minimum uniformly distributed design roof load shall be 25 psf per local ordinance
Winter heating design temperature is 2 degrees (99% dry bulb)
Table R301.5 is amended to require a minimum uniform live load of 40 psf in habitable attics and sleeping rooms.
Foundations with stem walls shall be provided with a minimum of one # 4 bar at the top of the wall and one #4 bar at the bottom of the footing. #4 vertical bars are required at 6 feet on center.
Basement walls to have one #4 horizontal bar at 4 feet on center. One #4 bar is also required horizontally and vertically around openings, extending 2 feet beyond the opening. One #4 bar to be placed diagonally at corners of openings subject to cracking. Vertical bars installed per IRC.
Unvented fuel-burning appliances are not allowed.
30” minimum crawl space depth measured from bottom of floor joist (per local resolution)
Please check the Residential New Home Design Guide to ensure your plans will pass the plan review.