A common question on window, door, and roof permits is “what wind load do I need?” There isn't a single answer. The design pressure depends on your address, your building, and where on the building the pressure acts. This guide explains what goes into it.
The specific numbers for your project come from the calculation, confirmed for your parcel. This is the method, not a value for any particular address.
Design wind speed (Vult)
The starting point is the ultimate design wind speed for your exact location, taken from the ASCE 7 wind hazard tool for the site, not a regional assumption. South Florida wind speeds are among the highest in the country, and they vary across the region.
Exposure and building height
Exposure category (how open the surrounding terrain is) and the building's mean roof height both change the velocity pressure. A taller building, or one on open coastal terrain, sees higher pressures.
Zones and effective wind area
Pressure isn't uniform across a wall or roof. Corners and edges (higher-numbered zones) see larger pressures than field areas, and smaller elements see higher pressures than large ones. The component-and-cladding method per ASCE 7-22 accounts for this, opening by opening.
Questions
What wind speed should I use for Miami?
The design wind speed comes from the ASCE 7 hazard tool for your exact parcel, not a single regional figure, and South Florida values are high. We confirm the value for your address rather than quote a number that may not apply.
Why do different windows on the same house need different pressures?
Because pressure depends on where the opening is (corner vs field zone) and its size. The component-and-cladding method assigns each opening its own required pressure, which is why a sealed schedule lists them individually.