Florida building code, NOA & impact ratings — explained

The High-Velocity Hurricane Zone (HVHZ)

The Florida Building Code designates Miami-Dade and Broward counties as the High-Velocity Hurricane Zone — the most demanding wind region in the United States, a legacy of Hurricane Andrew. In the HVHZ, opening-protection products must carry a Miami-Dade Notice of Acceptance (NOA).

The rest of coastal Florida falls within a Wind-Borne Debris Region (WBDR), where impact protection is required and products must hold a Florida Product Approval (FL#).

Miami-Dade NOA vs. Florida Product Approval

Think of it as two tiers of the same idea:

• Miami-Dade NOA — the strictest approval; required in the HVHZ. NOA-approved products are accepted statewide.
• Florida Product Approval — the statewide standard for the rest of the wind-borne debris regions. It is not sufficient on its own inside the HVHZ.

How impact windows are tested: TAS 201/202/203

• TAS 201 — Large Missile Impact: a 9-lb 2x4 fired at the glass at ~34 mph.
• TAS 203 — Cyclic Wind Pressure: thousands of pressure cycles simulating hurricane-force wind.
• TAS 202 — Uniform Static Air Pressure: structural and air/water performance.

Design Pressure (DP) ratings

A window's Design Pressure rating — commonly DP-30 to DP-60+ — measures the wind load it can withstand. The required DP depends on your home's wind zone, height, and exposure. Coastal and HVHZ homes need higher DP ratings; we spec the right rating for your location so you're neither under-protected nor overpaying.

The "25% rule"

If you replace more than 25% of a building's glazed opening area within 12 months, the code generally requires those replacements to meet current impact-protection standards. Practically, this means a large window project usually needs to be impact-rated anyway — so it often makes sense to do the whole home at once and capture the full insurance credit.