Wind Load Calc

What is a Wind Load Calculation?

A wind load calculation determines the design pressures that windows, doors, and other building openings must withstand during high-wind events like hurricanes. In Florida, building permits for window and door installations generally require these calculations to show the selected products can handle the expected wind forces at that specific location; requirements vary by jurisdiction.

Why Do You Need Wind Load Calculations?

• Building Permits - Most Florida building departments ask for wind load calculations with window and door permit applications; requirements vary by jurisdiction.
• Safety Compliance - Design pressures ensure installed products can survive hurricane-force winds.
• Product Selection - Know the required design pressures to select windows and doors that meet code.
• Inspector Approval - Professional, accurate reports help your projects pass inspection the first time.

How Are Wind Loads Calculated?

Wind load calculations in Florida follow the ASCE 7-22 standard. The process uses several engineering factors:

• Ultimate Design Wind Speed (V) - From ASCE 7-22 wind speed maps. In Florida, 130-185+ mph.
• Exposure Category (B, C, D) - Describes surrounding terrain and wind shielding.
• Velocity Pressure Coefficient (Kz) - Accounts for wind speed increase with height.
• External Pressure Coefficients (GCp) - Based on wall zones (Zone 4 interior, Zone 5 corners).
• Internal Pressure Coefficient (GCpi) - Based on building enclosure classification.

Who Needs Wind Load Calculations in Florida?

• Window contractors - required for every replacement window permit
• Door installers - entry doors, sliding glass doors, and storefronts
• General contractors - new construction and renovation projects
• Permit runners - pulling permits on behalf of contractors
• Owner-builders - homeowners doing their own permitted work
• Architects and designers - specifying products that meet code

Buildings Under 60 Feet

The Florida Building Code provides simplified wind-pressure methods for qualifying buildings with mean roof heights of 60 feet or less — the vast majority of residential and small commercial projects in Florida. Sealing and permitting requirements vary by project and jurisdiction; confirm with the applicable building department.