What the HVHZ is, and why it applies to you
Your home sits under the strictest residential building code in the continental United States. That is not marketing.
Two counties, both of them entire
The High Velocity Hurricane Zone is a geographic area defined by the Florida Building Code where the wind and debris requirements are stricter than in the rest of the state. It covers exactly two counties: Miami-Dade and Broward, both of them completely, not just the coastal strip.
That last part surprises people. Being ten miles inland does not put you outside it. There is no address in Miami-Dade exempt from the opening protection requirement.
It exists because of Andrew
Hurricane Andrew came ashore in south Miami-Dade in August 1992 as a category five. Much of the destruction was traced to failures of the building envelope: once a window or a garage door failed, the house pressurised from inside and roofs came off and walls collapsed.
Two things followed. Miami-Dade and Broward tightened their local codes and created the product control system that became the Notice of Acceptance. And Florida eventually unified its local codes into the Florida Building Code, keeping the HVHZ as a reinforced regime inside it. Everything strict about building here traces back to that one storm.
What it changes in practice
Inside the HVHZ, the Miami-Dade Notice of Acceptance is the product approval that matters, and testing follows the county’s own TAS protocols rather than the general national standards. Opening protection is mandatory across the whole zone with no exemption based on distance from the coast. And the installation has to follow the anchoring detail on the approval literally: substrate, spacing and embedment.
That last point is where a lot of otherwise good products end up failing an inspection. The approval covers the unit and how it is fixed, together. Fitting an approved window with the wrong anchors makes it an unapproved installation.
The thirty foot rule
Glazed openings up to thirty feet above grade have to be tested against the large missile. Above that height, the small missile applies. For a single family home or a townhouse, everything is under thirty feet, so everything needs large missile rated products. In a condominium tower the answer changes with the floor.
Questions about the HVHZ
I am miles from the beach. Does this really apply to me?
Yes. Both counties are covered in their entirety, and Miami-Dade sits far above the wind speed threshold that triggers the debris requirements anyway. Distance from the water changes what finishes and materials make sense; it does not change whether your openings need protection.
Is a state Florida Product Approval enough here?
In the rest of Florida it generally is. In the HVHZ the Miami-Dade Notice of Acceptance is what is expected, and it is what your reviewer will be looking for in the application.
Does the HVHZ make my windows more expensive?
It makes them better tested and more tightly specified, and yes, that costs more than the same product would elsewhere in the state. It is also why a Miami-Dade approval is respected across the country.
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