County Building Codes & Design Criteria
Adopted Building Codes:
2003 International Building Code (IBC)
2003 International Residential Code (IRC)
2003 Uniform Plumbing Code (UPC)
2003 Uniform Mechanical Code (UMC)
2005 National Electrical Code (NEC)
2003 International Existing Building Code (IEBC)
2003 International Fire Code (IFC)
Carson Valley Area (under 6,000 feet elevation)
Seismic Zone: IBC=D/IRC=D2 & E for some site specific areas
Wind Speed: 105 MPH (3-Second Gust)* Exposure: C
Snow Load: 30 psf **
Frost Depth: 18" (inches) minimum
Ice Shield Required: above 5,300 feet elevation
Soil Bearing: 1,500 psf maximum or site specific
Lake Tahoe Area (above 6,000 feet elevation):
Seismic Zone: IBC=D/IRC=D2 &E for some site specific areas
Wind Speed: 105 MPH (3-Second Gust)* Exposure: C
(Exposure B may be used in areas between 1/4 mile of the lakeshore & below the elevation of 7,200 feet.)
Snow Load: 150 psf (ground load)
Frost Depth: 24" (inches) minimum
Ice Shield Required: above 5,300 feet elevation
Soil Bearing: 1,500 psf maximum or site specific
Single Family Dwelling Design:
Minimum Roof Pitch: 4:12 (inches)
Maximum Building Height 35'-0" (feet)
Minimum Soffet Eaves (overhang): 18" (inches)
3 or More Gable ends and building offsets recessed/alcove or similar features
Minimum of 2-car off-street covered parking (carport or garage)
*Wind Speed (3-Second Gust): Prior to the 2003 IBC and IRC accepted engineering practice was to base the wind design on the "Fastest Wind Speed", which was defined as the highest recorded wind velocity averaged over the time it takes a mile of air to pass a given point. However, since short-term velocities due to gusts may be higher, the 203 IB provides wind design maps based on a 3-Second Gust. According to the 2003 IB Table 1609.3.1, the County minimum 105 MPH (3-Second Gust) wind speed an be converted to an 85 PH (Fastest Wind Speed): however, this must be clearly identified within the plans and the structural design calculations.
**30 PSF Snow Load: County policy requires that the 30 PSF ground snow load must be used as the design roof snow load. The 30 PSF snow load is the absolute minimum roof design load, design reductions will not be allowed to reduce the minimum roof design load.