The Basic Wind Speed used to design buildings and claddings in Southern California is highly variable, depending on which jurisdiction the project is in. Some jurisdictions define the Basic Wind Speed based on past experience; others rely solely on ASCE 7; and still others have no well-defined policy regarding this issue. There is particular variation in the areas in and around the Special Wind Regions in Southern California. Required wind speeds can vary by as much as 35 miles per hour, depending on the policy chosen by the jurisdiction; this can result in as much as an 87 percent increase in wind loads just from crossing from one jurisdiction to the next.
The shaded areas in this figure show a new Special Wind Region near Irvine and significant changes to the shape of the existing Special Wind Region along the San Gabriel and San Bernardino Mountain Ranges, as introduced in ASCE 7-22. More than a million people live in these special wind regions, several million more live in the surrounding areas, and these changes will be part of the 2025
California Building Code, so this is a critical issue that needs to be addressed.
The Structural Engineers Association of California (SEAOC) has been commissioning studies to help define the Basic Wind Speed in these Special Wind Regions. We are inviting building officials, plan checkers, and design engineers to collaborate in a charrette to discuss these changes and discuss what the appropriate Basic Wind Speed(s) should be in these areas.
The first hour will present recently completed studies that show what we have learned to date. The second hour will be a facilitated discussion to hear ideas regarding how to achieve a consistent approach to defining wind speed requirements in these areas. We are seeking ideas related to both technical recommendations and ways to organize the numerous jurisdictions in developing a common approach. We invite you to join us, share your experiences and expertise, and provide input at the charrette. The charrette will be informative, and SEAOC is offering it free of charge.
We look forward to seeing you there!
Gwenyth Searer, PE, SE
Gwen’s Bio: Gwenyth Searer is a Principal at Wiss, Janney, Elstner Associates, Inc. She is a licensed structural engineer in six western states, including California. She has 30 years of experience and is the Chair of the SEAOC Wind Committee.
Gwen’s Topic: Gwenyth will be speaking regarding the history of wind design and special wind regions in California, and she will be presenting the SEAOC Wind Committee’s recommendations regarding the Special Wind Regions in Southern California.
David Banks, PE, PhD
David’s Bio: Dr. David Banks has been with CPP wind engineering since 2000 and has been President since 2020. He is a member of the ASCE 7 wind loading subcommittee, the ASCE 49 Wind Tunnel Testing committee, and the ASCE Solar Manual of Practice committee.
David’s Topic: David will be discussing how wind speed data is used to develop recommendations for basic wind speeds in Special Wind Regions.
Emily Guglielmo, PE, SE
Emily’s Bio: Emily Guglielmo has over two decades of structural engineering experience and is currently a Principal with Martin/Martin. She Past President of SEAOC, Chair of the NCSEA Code Advisory Committee, and a voting member of the NCSEA, SEAOC, and ASCE 7-28 Wind Committees.
Emily’s Topic: Emily will be co-leading the charrette discussion regarding how best to handle the upcoming changes in the California Building Code and how to deal with the Special Wind Regions and the surrounding areas.
Stephen Kerr, PE, SE
Stephen’s Bio: Stephen Kerr is a Principal at Josephson Werdowatz and Associates, Inc. For nearly twenty years, he has participated in SEAOC and NCSEA committees, including serving as a past Chair of the SEAOC Wind Committee and helping to develop SEAOC’s Structural Seismic Design Manual and SEAOC’s Wind Design Manual. He is a licensed professional / structural engineer in five states, including California.
Stephen’s Topic: Steve will be speaking regarding the Division of the State Architect’s 2020 survey of Southern California jurisdictions in and around the Southern California Special Wind Region.