Why your roof, windows, doors, soffits, garage door, screens, and fences in Miami-Dade are held to stricter standards than the rest of the country, and what that means for the contractor you hire.
What HVHZ stands for
HVHZ is the High-Velocity Hurricane Zone. It is a designation in the Florida Building Code covering Miami-Dade and Broward counties (the southeastern coastal counties most exposed to Atlantic hurricanes). Inside HVHZ, building products and installation methods have to meet stricter wind-load, water-intrusion, and impact-resistance requirements than the rest of the state.
Why it exists
After Hurricane Andrew (1992) destroyed roughly 25,000 homes in south Miami-Dade, Florida rewrote the building code. Most damage in Andrew was not from the sustained wind, it was from missiles (debris) breaking openings and pressurizing homes from inside, lifting roofs. HVHZ tightened the rules on every penetration and impact surface so a hurricane cannot pull a house apart from inside out.
Check the wind-design criteria for your property
Ask the design professional or building department which wind-design criteria apply to your address and proposed work. Compare proposals using the same documented requirements, product specifications, installation details, and permit scope. A wind-speed figure alone does not establish a fixed roof-price premium over another city.
NOA, the approval document
A Notice of Acceptance (NOA) is a Miami-Dade County Product Control Division document certifying that a specific building product (a roof tile, a piece of impact glass, a soffit panel, a hardware anchor) has passed HVHZ testing. Every NOA has an expiration date and a specific installation method that must be followed exactly. If the contractor uses a different method, the NOA is void and the inspection fails.
Lookup tool: Miami-Dade BCCO Product Control Online (search by product or manufacturer). If a contractor cannot show you the NOA for the materials they propose, that is a red flag.
What HVHZ touches in your home
- Roof system: tile, shingles, underlayment, fasteners, sheathing nailing pattern, drip edge, ridge vents.
- Windows and doors: large-missile impact (9-pound 2x4 fired at 50 ft/s), small-missile impact, and cyclic pressure tests.
- Garage doors: rated for design wind pressures, hardened tracks, brace kits.
- Soffits and gable ends: vented soffit must be NOA-rated, gable ends braced for 175 mph uplift.
- Hurricane shutters and screens: roll-down, accordion, panel, and Bahama systems each have NOA test ranges.
- Fences over a certain height: chain link 6 ft+ and most aluminum/vinyl fences need engineered footings.
How to tell if your contractor knows HVHZ
- They reference the NOA number for the products they propose, on the proposal.
- They submit permit drawings to the right local building department (City of Miami vs City of Miami Beach vs unincorporated Miami-Dade vs Coral Gables, etc.).
- They know the difference between the Wind Mitigation Form (insurance discount) and the 4-Point Inspection (insurance underwriting).
- They mention the difference between "missile-impact" and "non-missile" zones, and price accordingly.
- Their FL contractor license at Pro.Miami's license verifier shows current insurance and an active certified status, not just a registered status.
If you are getting roofing, impact windows, hurricane shutters, garage door, screen enclosure, or fence work in Miami-Dade, HVHZ applies to your job. Submit a request on Pro.Miami and we will route you to contractors who do this every day.