ASD · LRFD · HVHZ · COMPONENTS & CLADDING
Pick the window that survives the pressure
Match a window, door, or storm shutter's Design Pressure rating to the wind pressures your building actually sees. Get the numbers right and the product approval follows.
DESIGN METHODS
ASD, LRFD & HVHZ — three lenses, one pressure
The wind doesn't change. The load combination you check it against does. Read the same C&C pressure through the right method.
ASD — Allowable Stress
Service-level wind is 0.6W: 60% of the ultimate pressure. Window DP ratings are published at this service level, so ASD pressures compare directly to a product's DP.
0.6 × ULTIMATELRFD — Load & Resistance
The wind load factor on strength-level wind is 1.0W — the full ultimate pressure straight off the ASCE 7 maps. No service reduction is applied at the ultimate level.
1.0 × ULTIMATEHVHZ — South Florida
The High-Velocity Hurricane Zone is Miami-Dade and Broward counties only. Openings need tested impact protection plus a Miami-Dade NOA or Florida Product Approval.
TAS 201 / 202 / 203There is no wind importance factor in ASCE 7-16 or 7-22. Risk category instead selects a different basic-wind-speed map — higher category, longer return period, higher design wind — not a fixed multiplier.
READING THE NUMBER
What each method hands the window
Same building, same wind. Choose the pressure your product datasheet was tested against.
| Method | Wind Level | Pressure | Use For |
|---|---|---|---|
| ASD | Service | 0.6 × ultimate (0.6W) | Matching published DP ratings |
| LRFD | Ultimate | 1.0 × ultimate (1.0W) | Strength-level structural design |
| HVHZ | Ultimate + impact | Per FBC / TAS protocols | Miami-Dade & Broward openings |
FOUR STEPS
How to pick the right DP-rated window
Design Pressure is the rated load a unit was tested to resist. Match it to the calculated Components & Cladding pressure on that opening.
1 · Locate the opening
Find each window or door's zone — interior wall (Zone 4) or corner (Zone 5). Corners pull harder.
C&C ZONE2 · Use effective area
Smaller effective wind area means higher pressure. A small fixed lite sees more psf than a wide slider — size it on its own.
AREA → PRESSURE3 · Compute both signs
Solve positive (pushing in) and negative (suction) pressures. Suction usually governs — the DP rating must cover the larger magnitude.
±GCp4 · Match DP ≥ pressure
Specify a unit whose Design Pressure meets or beats the governing C&C value. In HVHZ, confirm a current NOA or Florida Product Approval too.
DP ≥ DEMANDWHY ENGINEERS RUN IT HERE
Numbers your plan reviewer accepts
Permit-ready output
Code-traceable ASCE 7 wind pressures formatted for window, door, and shutter submittals.
ASCE 7-16 / 7-22Solving wind since 2002
More than two decades across multiple ASCE 7 editions — used by engineers, architects, and contractors.
24+ YEARSHVHZ aware
Built to flag Miami-Dade and Broward openings where NOA / Florida Product Approval and TAS impact testing apply.
FBC HVHZSTART WITH THE PRESSURE
Get the C&C numbers, then spec the DP
Run your building's wind load pressures and carry the governing value straight onto your product schedule.