HVHZ (High-Velocity Hurricane Zone)

Why HVHZ Rules Are Stricter

Miami-Dade and Broward Counties are the only two jurisdictions carrying the official HVHZ designation, a legacy of the damage seen in past major hurricanes making landfall in South Florida. Rather than leaving wind design to the baseline ASCE 7-22 load provisions that apply everywhere else in the state, the Florida Building Code (FBC) layers HVHZ-specific chapters on top — covering product approval, attachment testing, and edge/corner uplift zones in more detail than standard ASCE 7 alone. In practice this means the local AHJ in these counties reviews solar submittals against a stricter checklist than a building department elsewhere in Florida or the rest of the US would apply.

Structural and Attachment Implications for PV

The 170+ mph design wind speeds and uplift pressures that can exceed 50 psf push most HVHZ rooftop PV projects toward mechanically-attached racking rather than ballasted racking — the friction-and-weight approach that works on many lower-wind commercial roofs simply can’t be justified at HVHZ uplift levels without an unusually detailed engineering analysis. Racking, fasteners, and roof attachment components used in HVHZ installations typically need to carry FM Global Approval or equivalent third-party listing, since insurance carriers writing policies in these counties often condition coverage on it. On the code side, whether a project falls under the IBC (commercial) or IRC (one- and two-family residential) shapes which structural provisions and permit forms apply, so confirming that classification early is one of the first steps in an HVHZ PV design.

Key Takeaways

• HVHZ = Florida hurricane high-wind zone (Miami-Dade, Broward).
• Florida Building Code HVHZ provisions supplement ASCE 7.
• Design wind speeds 170+ mph; uplift can exceed 50 psf.
• FM Global Approved equipment often required by insurance.
• Specialized racking and mounting expertise needed.

Related Reading

HVHZ is ultimately a permitting problem as much as a structural one — the stricter product approval and attachment documentation that Miami-Dade and Broward require has to make it through the local AHJ before a system can be installed, so the general mechanics of that process matter even though HVHZ itself is Florida-specific. Our checklist on how to submit a solar permit package to an AHJ walks through what a reviewer typically expects to see, and because the IBC/IRC classification above changes which permit path applies, commercial vs. residential solar permit design is a useful companion read for scoping which set of requirements a given HVHZ project falls under. For teams fielding recurring questions from EPCs on permit submittals more broadly, our solar permit design FAQ covers many of the same “what does the reviewer actually want” questions that come up on HVHZ projects.