Master DP ratings, impact resistance requirements, and product selection for windows and doors in high-wind regions. Match calculated pressures to the right products.
Calculate Window PressuresDesign Pressure (DP) = Maximum wind pressure a window/door can resist. A DP 50 product handles +50 psf and -50 psf.
Selection rule: Product DP rating must exceed your calculated C&C pressure for that location. Zone 5 corners need higher ratings than Zone 4 field areas.
Impact zones: Windborne debris regions require impact-resistant products OR protective shutters meeting ASTM E1996.
Design Pressure ratings indicate the structural wind load capacity of fenestration products. This is the most critical specification for window and door selection in wind-prone areas.
| DP Rating | Typical Use | Approximate Wind Speed* |
|---|---|---|
| DP 15 | Low-wind inland, residential | 95-105 mph |
| DP 25 | Moderate wind, light commercial | 105-115 mph |
| DP 35 | Coastal areas, mid-rise | 115-125 mph |
| DP 50 | High-wind coastal, commercial | 125-140 mph |
| DP 65+ | HVHZ, high-rise, extreme wind | 140+ mph |
*Approximate correlations for Risk Category II, Zone 4. Actual requirements vary by height, exposure, zone, and internal pressure.
Laminated glass with interlayer. Resists debris impact and maintains envelope integrity. Required in windborne debris regions or when no shutters provided.
Standard windows protected by approved hurricane shutters (accordion, roll-down, panel). Shutters must meet ASTM E1996 for debris impact.
Double or triple pane for energy efficiency. Can be impact-resistant if one lite is laminated. Check that DP rating accounts for full assembly.
Aluminum-framed commercial systems. Available in high-DP configurations. Frame and glass must both meet pressure requirements.
ASCE 7 Section 26.12 defines windborne debris regions where glazed openings require protection:
Zone 1 (Coastal): Within 1 mile of coastal mean high water line where basic wind speed V ≥ 130 mph
Zone 2 (Inland): Anywhere the basic wind speed V ≥ 140 mph
Hawaii: Entire state is in windborne debris region
In windborne debris regions, glazed openings must be protected by one of:
If wind-borne debris breaks a window, the building becomes "partially enclosed" with dramatically higher internal pressure. This can double or triple roof uplift loads and cause catastrophic structural failure. Protecting openings maintains envelope integrity.
Different wall zones require different DP ratings. Always check both Zone 4 (field) and Zone 5 (corners) requirements.
| Location | Calculated Pressure | Minimum DP | Recommended |
|---|---|---|---|
| Zone 4 (Field) | +38/-52 psf | DP 55 | DP 60 |
| Zone 5 (Corners) | +45/-72 psf | DP 75 | DP 80 |
| Second Floor Zone 4 | +42/-58 psf | DP 60 | DP 65 |
| Second Floor Zone 5 | +52/-82 psf | DP 85 | DP 90 |
Create a window schedule showing:
Doors have similar requirements to windows but with additional considerations for size, operation, and use.
Hinged single or double doors. Must resist positive and negative pressures. Impact-rated options available with laminated glass lites.
Large glazed area requires high DP ratings. Impact-resistant versions use laminated glass. Frame tracks must maintain integrity.
Large openings with high failure risk. Reinforced doors with bracing for high-wind areas. Critical for maintaining envelope.
Double-hinged doors with glazing. Both leaves must resist pressures and remain latched. Consider multi-point locking hardware.
Garage doors are often the weakest link in the building envelope:
The Florida Building Code High-Velocity Hurricane Zone (HVHZ) covering Miami-Dade and Broward counties has the most stringent fenestration requirements:
See our HVHZ Complete Guide for detailed requirements.
Even properly rated products can fail if installation is inadequate. Key installation requirements:
Major window and door manufacturers provide wind load selection tools:
Request product submittals showing tested DP ratings, impact certification, and installation details for your specific project requirements.
WindLoadCalc.com calculates C&C pressures by zone for accurate product selection. Get Zone 4 and Zone 5 pressures at each floor level to specify the right DP ratings.
Try Wind Load Calculator