The High Velocity Hurricane Zone
HVHZ is where the strictest wind-load and product-approval rules in the country apply — Miami-Dade and Broward counties, where ultimate design wind speeds typically run ~170–180 mph (Risk Cat II) and vary by site.
The four enhanced demands
HVHZ areas face the highest hurricane exposure in the continental U.S. — so the Florida Building Code raises the bar on four fronts.
Extreme Wind Speeds
Ultimate design wind speeds typically ~170–180 mph (ASCE 7-22, Risk Cat II) — higher on the very highest Risk Cat IV coastal maps. Always varies by site.
NOA-Approved Products
Every window, door, shutter and roof assembly needs a Miami-Dade NOA or equivalent certification.
Wind-Borne Debris
Impact-rated glazing or approved shutters on every building — regardless of distance from the coast.
Strict Inspections
Enhanced inspection protocols plus third-party testing verification under FBC enforcement.
What triggers HVHZ designation
Two criteria define an HVHZ area: a wind-speed threshold and statutory coastal designation.
Wind-Speed Criterion
A high-wind region — HVHZ corresponds to the historical wind-speed basis of 130 mph or greater. Today the statutory HVHZ counties carry ASCE 7-22 Risk Cat II design speeds of roughly 170–180 mph, varying by site.
Coastal Proximity
Specific coastal counties designated by the FBC regardless of the wind-speed map.
Where HVHZ rules apply
Florida codifies HVHZ statewide; comparable high-wind coastal provisions govern parts of the Texas Gulf coast and Hawaii.
Miami-Dade County
Entire county is HVHZ — the most stringent rules. Miami-Dade NOA required.
Broward County
Entire county is HVHZ. Broward NOA or Miami-Dade NOA accepted.
Other High-Wind Coast
Portions of Monroe, Palm Beach & Collier may qualify by wind-speed map; the Texas Gulf coast and Hawaii carry comparable high-wind provisions.
Run HVHZ-aware pressures with the Florida Wind Load Calculator →
The key differences
HVHZ is substantially more demanding than standard zones — the provisions an engineer or contractor notices first.
| Requirement | Standard (Non-HVHZ) | HVHZ · Miami-Dade / Broward |
|---|---|---|
| Design wind speed V (Risk Cat II) | ~120–170 mph | ~170–180 mph (varies by site) |
| Product approval | Florida Product Approval (basic) | Miami-Dade NOA / Broward NOA |
| Wind-borne debris protection | Within 1 mi of coast at V ≥ 140 mph | ALL buildings, any distance |
| Impact testing standard | ASTM E1996 / E1886 | Miami-Dade TAS 201 / 202 / 203 |
| Window / door design pressure | Per ASCE 7 wind loads | ASCE 7 + Protocol PA-201/203 |
| Typical residential window DP | DP-30 to DP-50 | DP-50 to DP-80+ |
| Cost premium vs standard | Baseline | +30% to +60% |
| Inspections | Standard dept. inspections | Enhanced + third-party verification |
Miami-Dade NOA & the TAS protocols
A Notice of Acceptance from the Miami-Dade Building Code Compliance Office (BCCO) is the most stringent hurricane-product approval in the U.S.
TAS 201
Impact resistance — large missile, 9 lb 2×4 at 50 fps.
TAS 202
Cyclic pressure testing — 9,000 pressure cycles.
TAS 203
Water resistance after impact & cyclic loading.
Verify NOA status before you buy
Search the BCCO Product Control database by manufacturer, product or NOA number; confirm it is current and active, that your exact model is listed, and review the installation requirements. Expired or invalid NOAs cause permit denial, costly tear-out, denied insurance claims and installer liability.
How high the ratings climb
DP is the maximum wind pressure (psf) a component withstands without failure — tested per ASTM E330 for both positive (push) and negative (suction) loads. HVHZ pushes those ratings far higher.
| Location / Zone | Residential Window DP | Commercial Curtain Wall DP |
|---|---|---|
| Inland Non-HVHZ · V ≈ 120 mph | DP-30 to DP-40 | DP-40 to DP-60 |
| Coastal Non-HVHZ · V ≈ 150 mph | DP-40 to DP-50 | DP-60 to DP-80 |
| HVHZ · V ≈ 170–180 mph (Risk II) | DP-50 to DP-70 | DP-80 to DP-100 |
| HVHZ · highest Risk IV coastal map (≈ 195 mph) | DP-70 to DP-90+ | DP-100 to DP-150+ |
HVHZ residential window in Miami Beach
Single-family home in Miami-Dade County HVHZ — corner wall zone, worst case.
Inputs
The math
qh = 0.00256 · Kh · Kd · V² qh = 0.00256 · 1.12 · 0.85 · 175² qh = 74.6 psf p = qh · G · Cp (G = 0.85) Zone 4 corner: Cp = −1.6 p = −101 psf (suction) p = +63 psf (pressure)
Required rating must exceed ±101 psf → specify DP-55 or higher.
Selection: impact-rated aluminum window, Miami-Dade NOA, DP-110, tested per TAS 201/202/203.
Six rules that keep HVHZ projects compliant
Compliance lives in the details — product selection, exact installation, and documentation.
1 · Verify NOAs Early
Check status for every product before ordering — via the official BCCO database, not a sales rep.
2 · Follow NOA Drawings
Match approved details exactly. Wrong fastener spacing or anchors voids the approval.
3 · Document Everything
Keep NOA letters, product labels, install photos and inspection reports on file.
4 · Third-Party Inspections
Coordinate inspection agencies early — HVHZ adds reviews beyond the building department.
5 · Use Certified Installers
Many products require manufacturer-certified technicians — verify credentials first.
6 · Plan for Higher Costs
Budget +30–60% for HVHZ products. Impact windows can run $100–$200+ per sf installed.
Common compliance mistakes to avoid
Skip the protocols. Run the pressures.
Our sister site WindLoadCalc.com automates HVHZ design pressures — Miami-Dade and Broward wind-speed lookup, latest ASCE 7-22 C&C calculations, DP recommendations and NOA compliance checks.