GCs building in Florida's High Velocity Hurricane Zone face a binary choice on most projects: impact-rated glazing or an approved opening protection system. Here's what actually matters for commercial construction.
The Code Reality
Florida Building Code Section 1609 requires that all glazed openings in buildings be protected against wind-borne debris in wind design categories requiring such protection. In the HVHZ — Miami-Dade and Broward counties — that protection standard is the most demanding in the country: large missile impact testing at 50 fps with a 9-pound 2x4.
There are two ways to meet that requirement: install impact-rated glazing products with a valid Miami-Dade Notice of Acceptance (NOA), or install approved opening protection systems (hurricane shutters) over non-impact glazing.
For residential applications, the shutter option is still common. For commercial construction, the calculus is almost always different.
Why Commercial Projects Specify Impact Glass
On a commercial building, hurricane shutters create operational problems that most building owners aren't willing to accept:
Deployment Requirements
Shutters require someone to physically deploy them before a storm. On a 20-story building, that's a substantial operation — and one that needs to happen while the storm is approaching, which is exactly when people are trying to evacuate. Most commercial buildings use automated rolldown shutters to address this, but that adds significant cost.
Ongoing Maintenance
Mechanical shutter systems require regular maintenance — motors, tracks, and hardware that are exposed to Florida's coastal environment. Impact glass has no moving parts and requires no storm preparation.
Building Envelope Performance
Many building owners want to occupy or operate their facilities during or immediately after a storm event. With shutters deployed, that's impractical — the building is essentially blacked out. Impact glass allows continued operations regardless of storm conditions.
Aesthetic and Leasing Impact
Commercial tenants in Class A office or retail rarely want to lease space in a building that deploys rolling shutters. Impact glass maintains the building's aesthetic in all conditions.
The Cost Comparison
Impact glass costs more upfront than standard glazing with shutters on a per-opening basis.
But that comparison isn't the right one. The right comparison is impact glass vs. non-impact glass plus a deployed hurricane protection system. When you add automated rolldown shutters, their installation cost, their ongoing maintenance, and their operational impact, impact glass is frequently the more the more the more the more cost-efficient solution over the building's lifecycle.
For new construction, the structural cost of integrating shutters — blocking for motors, conduit runs, control systems — often tips the analysis decisively toward impact glass.
When Shutters Still Make Sense
There are situations where shutters remain the appropriate choice:
- Historic buildings where the original glazing must be preserved
- Buildings where the glazing is scheduled for replacement in the near term anyway
- Industrial facilities where aesthetics are genuinely irrelevant and budget is the primary constraint
- Openings that don't require storm protection under the applicable code
The ACG Recommendation
For virtually every commercial new construction project in the HVHZ, ACG recommends impact-rated glazing. ESWindows and Slimpact systems provide the large missile impact performance Florida's codes require, with valid Miami-Dade NOA listings that give your inspector the documentation they need.
The submittal process is straightforward when the products have valid listings. The installation is no more complex than standard glazing. And the building owner gets a fully operational facility in any weather condition, with no moving parts to maintain and no storm preparation protocol to execute.
If you're evaluating impact glass vs. shutters for an upcoming project, send us your plans. We'll give you a frank assessment of what makes sense for your specific situation and a competitive scope for the impact glazing option.
Installation Considerations
One dimension of the impact vs. shutter decision that often gets overlooked is the installation complexity. Hurricane shutter systems — particularly motorized rolldown shutters — involve electrical rough-in, motor mounting conditions, soffit and header blocking requirements, and control system wiring that needs to be coordinated during framing. That coordination often doesn't happen at the right time, resulting in field conflicts and change orders.
Impact glass installation is essentially the same process as standard glazing. The product is heavier and requires stronger anchoring systems, but the coordination sequence is familiar to any experienced glazing contractor. For GCs who've managed both types of installations, the coordination simplicity of impact glass is a meaningful advantage on busy projects.
Insurance and Building Value
From a building owner's perspective, impact glass typically carries insurance premium benefits over buildings with shutter systems. Florida property insurers recognize that impact-rated glazing provides passive protection that doesn't depend on a human action before a storm, and many provide premium credits accordingly. The building value calculation also often favors impact glass — permanent protection is a more marketable building feature than installed shutter hardware.
For GCs who advise owners on scope decisions, these downstream considerations are worth raising. A modest upfront premium for impact glass can deliver years of insurance savings and a more valuable, more marketable building.