What Is the HVHZ?
The High Velocity Hurricane Zone (HVHZ) encompasses all of Miami-Dade County and Broward County—two of Florida's most populous regions. Established after Hurricane Andrew devastated South Florida in 1992, the HVHZ imposes the most stringent wind and impact requirements for building construction in the United States.
In the HVHZ, every exterior glazing product must either be impact-rated with a valid Miami-Dade Notice of Acceptance, or protected by an approved shutter system. There are no exceptions. The code is enforced through rigorous product approval, shop drawing review, and field inspection processes.
For developers and contractors, the implications are significant: glazing specifications must be verified against the Miami-Dade Product Control database, product lead times are longer, installation must be inspected by authorities having jurisdiction, and non-compliant installations can result in failed inspections, removal, replacement, and project delays.
NOA vs. FPA: Understanding the Approval Process
This is where many developers and contractors stumble. The HVHZ uses Miami-Dade Notice of Acceptance (NOA) approvals, which are different from Florida Product Approvals (FPA) used in the rest of Florida.
Miami-Dade Notice of Acceptance (NOA): An NOA is a product-specific approval issued by Miami-Dade County's Product Control Division. It certifies that a product has been tested and evaluated to meet the enhanced wind and impact requirements of the HVHZ. NOAs are more stringent than FPAs. They require testing to the large missile impact criteria of ASTM E1886/E1996 and are approved only for specific conditions.
Florida Product Approval (FPA): An FPA is issued by the Florida Building Commission and is used throughout Florida outside the HVHZ. FPAs may require impact-rated or wind-borne-debris-rated glazing, but the testing and approval criteria differ from HVHZ requirements. A product with an FPA cannot be used in the HVHZ unless it also carries an NOA.
This distinction is critical: A product that is "impact-rated" or has a "Florida approval" is not necessarily HVHZ-compliant. The product must carry a Miami-Dade NOA with conditions that match your specific project installation.
Impact Testing Standards: ASTM E1886 and E1996
The HVHZ requires impact glazing tested to ASTM E1886 (standard practice for performance testing of exterior windows, curtainwall, and doors subjected to missile impact) and ASTM E1996 (standard specification for performance of exterior windows, curtainwall, doors, and impact protective systems subjected to missile impact and pressure cycling).
These standards simulate hurricane-driven wind-borne debris impact. Testing involves shooting large missiles (9-pound wood 2x4s) and small missiles (salt balls) at glazing specimens at specified velocities. The glazing must not break or allow projectiles to pass through. If breakage occurs, the glazing must retain its integrity and not create dangerous shards.
For HVHZ projects, the design wind speed for your specific location determines the impact test velocity. Miami-Dade publishes wind speed zones, and glazing must be impact-tested to the velocity corresponding to your project location. For example, coastal properties may require testing at higher velocities than inland locations.
The Code Compliance Process
Step 1: Obtain Design Wind Speed and Load Requirements. Your structural engineer will determine the design wind speed for your building location based on the International Building Code and Miami-Dade amendments. This wind speed drives glazing impact test requirements and performance specifications.
Step 2: Specify Impact-Rated Products with NOAs. Your architect and structural engineer will specify glazing products that carry NOA approvals matching your design wind speed and building conditions. This specification must reference the specific NOA number and revision, not just "impact-rated glazing." ACG's estimating team verifies all NOA approvals against the Miami-Dade Product Control database.
Step 3: Submit Shop Drawings and Product Documentation. The glazing contractor submits shop drawings and NOA documentation to the contractor and design team for approval. Authorities having jurisdiction also review glazing submittals. All NOAs must be current and match the installed conditions (frame size, glass thickness, specific product model).
Step 4: Installation Inspection. HVHZ installations are subject to special inspection requirements. A third-party special inspector verifies that installed glazing matches approved shop drawings and that all products carry current NOAs. This inspection occurs during installation and before walls are closed.
Step 5: Final Approval. After inspection and approval, the building department issues a notice of completion. Non-compliant installations are not approved and must be corrected or replaced before the building can proceed to occupancy.
Common Mistakes That Cause HVHZ Compliance Issues
Mistake 1: Specifying "Impact-Rated" Without Verifying NOA. Many projects specify impact-rated glazing without confirming that products carry valid Miami-Dade NOAs. Contractors then submit products with FPAs or NOAs from other jurisdictions, which will not pass inspection. Always verify NOA status before procurement.
Mistake 2: Using Expired or Revised NOAs. NOAs have validity periods and are updated periodically. Installing a product with an expired NOA or an outdated revision will fail inspection. Always verify that the installed product's NOA number and revision match the approved submittal and are currently valid.
Mistake 3: Assuming All Manufacturers' Products Are HVHZ-Approved. Not all products from major manufacturers carry HVHZ NOAs. Some manufacturers have limited HVHZ-approved product lines. Verify NOA status early in the specification process, not during construction.
Mistake 4: Mismatching Installation Conditions. NOAs often specify conditions of approval—frame size limits, glass thickness ranges, specific installation details. Installing products outside these conditions violates the NOA and will fail inspection. The special inspector verifies all conditions match the installed system.
Mistake 5: Insufficient Coordination Between Glazing Contractor and GC. Lack of communication about NOA requirements and inspection deadlines causes schedule delays and rework. Clear coordination and early notification of special inspection requirements prevents problems.
Lead Times and Project Planning
HVHZ-approved products often have longer lead times than standard glazing. Some products require 8-12 weeks fabrication, and certain specialty items may take even longer. Budget additional lead time when planning HVHZ projects.
Additionally, special inspection scheduling can affect installation sequence. Inspections must occur during installation, which means glazing work cannot be compressed into a short window. Plan schedules accordingly.
Working With an Experienced HVHZ Contractor
ACG specializes in HVHZ compliance. Our team verifies NOA status, coordinates with special inspectors, understands conditions of approval, and manages the entire compliance process. We maintain up-to-date access to the Miami-Dade Product Control database and have established relationships with manufacturers and building departments.
For HVHZ projects, working with a contractor that understands the regulatory environment prevents costly rework and schedule delays.