Wind Hazard Zones for Louisiana

Patricia Skinner, Capello, Jr. Henry T., Reichel, Claudette Hanks

2012 IRC Wind Speed Map - State of Louisiana. Louisiana adopted the Wind Speed Map from the 2012 IRC, effective January 1, 2013. Click the image to enlarge.

2003 IRC/IBC Wind Speed Map - State of Louisiana.The 2003 map was used in Louisiana from 2006 throuigh 2012. Click the image to enlarge.

Basic Wind Speeds (BWS) for Louisiana come from a map (top right) included in the 2012 IRC. At present, Louisiana has based its residential building code on the 2009 IRC, but effective January 1, 2013, is referencing the BWS for the 2012 building code. The wind hazard zones for Louisiana from first adoption of residential building codes (2006) until January 1, 2013, are shown in the Wind Speed Map (bottom right).

  • South Louisiana is in a hurricane zone. The closer to the Gulf, the higher the wind risk.
  • Tornadoes are common in North Louisiana and can be embedded in hurricanes.
  • High winds can put great forces on a building, including shear loads (causing racking), lateral loads (push, pull) on wall connections and uplift on the roof. 
  • A house in an unobstructed open clearing or within 1,500 feet of open water is susceptible to higher wind forces from unobstructed winds. 
  • Structural reinforcements can enable homes to withstand hurricane-force winds.
  • Rather than fortify the entire structure against winds caused by tornadoes, a specially reinforced “safe room” can more economically provide a shelter that can remain standing even when a house is destroyed.

    Go interactive wind speed map for Louisiana

PLEASE NOTE:  Minimum design standards for wind loading have been developed by the American Society of Civil Engineers (ASCE) and are referenced in the International Building Code and International Residential Code at the International Code Council Web site Louisiana enacted statewide enforcement of the "latest version" of the IRC beginning January 1, 2007.

Although the latest version of the IRC at time of adoption by the Louisiana State Uniform Construction Code Council (LSUCCC) was the IRC 2006, the wind design provisions from IRC 2003 were held in effect. In December 2012, the LSUCCC published an emergency rule that substitutes Figure R301.2(4)A Basic Wind Speeds of the 2012 IRC, for Figure R301.2(4) Basic Wind Speeds For 50-Year Mean Recurrence Interval of the 2003 IRC. The change is effective January 1, 2013.

The LSUCCC officially adopted a wind-speed coded list of Zip+4 delivery routes for determining the relevant wind speed for building construction. The Zip+4 lists, with wind speeds, are posted by parish on the LSUCCC Web site at The GIS data-layer used to derive the official Zip+4 list for LSUCCC was incorporated into the geographic interface at: This data-layer and LSUAgCenter application were based on BWS from the 2003 IRC (ASCE 7-05) but have been replaced by BWS data from ASCE 7-10, which is incorporated in the 2012 IRC.

The wind speed geographic interface imports ground elevation data from the U.S. Geological Survey. Windspeed and elevation data are for planning purposes only and do not take the place of determinations made by local officials and/or professional surveyors.

12/28/2006 4:08:36 AM
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