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Codes and Design Criteria
- Building Codes
- Municipal Codes
- Snow Loads
- Wind Loads
- Seismic
- Soils
- Flood Hazards
- Rainfall
- Climate Zone
- Weathering
- Termite
- Winter Design
- Ice Shield Underlayment
- Air Freezing Index
- Mean Annual Temp
Building Codes
Adopted Building Codes
Effective July 1, 2023:
- 2021 International Building Code, including appendices C & J
- 2021 International Residential Code, including appendix AQ
- Except residential provisions of Chapter 11, Energy Efficiency.
- 2021 International Plumbing Code
- 2021 International Mechanical Code
- 2021 International Fuel Gas Code
- 2020 National Electrical Code issued by the National Fire Protection Association (NFPA)
- 2015 International Energy Conservation Code (residential)
- 2021 International Energy Conservation Code (commercial)
- 2021 International Existing Building Code
- 2021 International Swimming Pool & Spa
- 2006 International Wildland-Urban Interface Code
- Manufactured Home:
- Subsection 15A-2-104(2), the HUD Code
- Subsection 15A-2-104(1), Appendix AE of the 2021 International Residential Code
- Subsection 15A-2-104(1), 2005 NFPA 225 Model Manufactured Home Installation Standard, issued by the NFPA
- Historic Buildings:
- Subsection (3) for standard guidelines pertaining to plaster on a historic property, as defined in Section 9-8-302, the US Department of the Interior Secretary's Standards for Rehabilitation and Guidelines for Rehabilitating Historic Buildings
- Adopted per the Utah Code, Title 15A - State Construction and Fire Codes Act
- Consistent with Title 65A, Chapter 8, Management of Forest Lands and Fire Control, the Legislature adopts the 2006 edition of the Utah Wildland Urban Interface Code, issued by the International Code Council, with the alternatives or amendments approved by the Utah Division of Forestry, as a construction code that may be adopted by a local compliance agency by local ordinance or other similar action as a local amendment to the codes listed in this section, and Statewide Amendments are incorporated as Part of the State Construction Code.
Snow Loads
- Ground Snow Loads: The actual snow loads vary depending upon elevation. For all projects located at, or below, 4,239 feet mean sea level the ground snow load (Pg) shall be a minimum of 28 pounds per square foot. For elevations above 4,239 feet mean sea level please visit https://utahsnowload.usu.edu as referenced in Section 15A of Utah’s “State Construction and Fire Codes Act”.
- Roof Snow Loads: Shall be determined per Chapter 7 of ASCE 7-16.
- Seismic Snow: At locations where the roof snow load exceeds 30psf a percentage of the snow load must be considered in the effective seismic weight of the structure per Section 15A-3-107 of Utah’s “State Construction and Fire Codes Act”.
Wind Loads
- Speed: All wind speeds listed below are 3-second gusts at 33 feet above the ground.
- Residential: 115 mph
- Commercial (see IBC Figures 1609.3(1-4):
- Risk Category I = 100 mph
- Risk Category II = 105 mph
- Risk Category III = 110 mph
- Risk Category IV = 115 mph
- Exposure: Site-specific (per Chapter 26 of ASCE 7-16). Typically, “B” or “C”.
Seismic
- Seismic Design Category:
- Residential: D2
- Commercial: D
- Site-specific: Because ground motions tend to vary substantially throughout the city, the mapped spectral accelerations (SS & S1) should be obtained by considering the site-specific address or latitude and longitude values and obtaining the ground motions from the Applied Technology Council’s “ATC Hazards by Location” tool (https://hazards.atcouncil.org/).
- Site-Specific Parameters (unless ASCE 7 exceptions are met):
- S1 ≥ 0.2g and Site Class ‘D or E’ → A ground motion hazard analysis (GMHA) must be provided.
- SS ≥ 1.0g and Site Class ‘E’ → A ground motion hazard analysis (GMHA) must be provided.
- Site Class ‘F’ → A site response analysis (SRA) must be provided.
Soils
- Frost Depth: 30 inches. This may increase at higher elevations.
- Site Class: Site-specific. For projects not requiring a geotechnical report (see below) Site Class ‘D’ can be assumed per Section 20.1 of ASCE 7-16 but ground motions must be adjusted per IBC 1613.2.3.
- Allowable Bearing Pressures:
- Foundation pressure: 1,500psf, per IRC Table R401.4.1 and IBC Table 1806.2.
- Lateral pressure: 100psf/f, per IBC Table 1806.2.
- The above-listed values are the maximum allowable values unless listed otherwise by a site-specific geotechnical report complying with IBC 1803.6 and IBC 1803.5.5, as applicable.
- Site-specific Geotechnical Report:
- General: All geotechnical reports submitted for permit issuance must be dated no later than two years from the permit application date. Outdated reports must be accompanied by a letter from a qualified geotechnical engineer stating that the report requirements are still valid or stating what items may have changed.
- Residential: Residential projects meeting one or more of the following requirements must provide a site-specific geotechnical report meeting the requirements of IBC 1803.6:
- Where the building footprint is greater than 3,000 square feet or has a gross square footage of 6,000 square feet or greater; or
- Where the grade supporting the structure has a slope equal to or greater than 20 percent; or
- Where the building is to be built on a lot in which a previous structure once existed.
- Commercial: All commercial projects require a site-specific soil report meeting the requirements of IBC 1803.6 and IBC 1803.5.5, as applicable. Additions to existing facilities of less than 3,000 square feet are exempt from this requirement.
FLOOD HAZARDS
- Flood Hazard Areas:
- Residential: Buildings and structures located in flood hazard areas (i.e. Flood Zones A or V) must comply with IRC R322.
- Commercial: Buildings and structures located in flood hazard areas must comply with IBC 1612, Chapter 5 of ASCE 7-16 and ASCE 24-14.
- Floodways: Buildings and structures located in identified floodways must be designed and constructed in accordance with ASCE 24-14.
- Interactive Flood Zone Map: Available at the following WEB LINK.
RAINFALL
The average annual rainfall is 16 inches.
CLIMATE ZONE
5B
WEATHERING
Severe
TERMITE
None to Slight
WINTER DESIGN TEMP
8°F
ICE SHIELD UNDERLAYMENT
Yes
AIR FREEZING INDEX
≤ 1500
MEAN ANNUAL TEMP
45°F
- List current codes w/ link to State Amendments
- USU Snow Load site
- Wind Loads
- Climate Zone
- ASHRAE information
- Floodplain map