The Washington State Building Code includes the 2015 International Building Code (IBC) and International Residential Code (IRC) as adopted pursuant to the Cowlitz County Code (CCC) Title 16. The following design criteria are applicable within the jurisdiction of Cowlitz County.
Commercial structures, IBC Section 1609 –
Ultimate Design Wind Speed Vult: Figures 1609.3(1), 1609.3(2) and 1609.3(3).
Exposure Category shall be established by the designer in accordance with Section 1609 or ASCE 07.