A Homeowner’s Guide to Choosing Impact Windows

Fenestration /fĕn″ĭ-strā′shən/: the design and placement of windows in a building.¹

In Florida, where hurricanes and severe storms test every structure- the design, installation, and performance of your home’s windows are essential for safety, aesthetics, and long-term durability. Whether you’re designing a new home or upgrading an existing one, the right windows are some of the most critical components you’ll invest in.

When searching for “the best” impact windows, it’s tempting to focus on brand names. However, no single manufacturer is universally superior. The effectiveness of a window depends on how it performs under real-world conditions, the materials used, the certifications it holds, and how well it’s installed – even a highly rated window can underperform if installed incorrectly or if the surrounding structure is compromised.

Understanding Ratings and Certifications

Impact windows are rigorously tested to withstand hurricane-force winds, flying debris, and sudden pressure changes. There are three main standards for window products that homeowners should be aware of when shopping: ASTM E1886 and ASTM E1996, which set the criteria for windows and doors exposed to windborne debris and fluctuating pressures, and AAMA 506, which covers impact and cycle testing (repeated pressure simulation).² Windows that meet all three standards can earn the AAMA Gold Label Certification, an industry-recognized mark of hurricane-ready performance.

During testing, windows are struck with projectiles like two-by-four pieces of wood at specific speeds, simulating airborne debris during a storm. After impact, the window must withstand cycles of pressure similar to hurricane winds without compromising structural integrity. The resulting certified windows are designed to protect the occupants as well as reduce wind and water damage to the home.

Frames and Glass

The materials used in both the frame and glass play a critical role in performance.

• Glass: Impact windows combine tempered glass with laminated layers and a thermal spacer, often incorporating polyvinyl butyral (PVB) interlayers. This combination is what provides both strength and flexibility, so the window can absorb the impacts without shattering into dangerous shards. High-impact windows often have multiple laminated layers for extra protection in areas prone to Category 4 or 5 hurricanes.
• Frames: The most common frame materials for impact windows are vinyl and aluminum.
  • Vinyl frames are low maintenance; resistant to moisture, rot, and insect damage; and provide the highest energy efficiency. But, they tend to be the most expensive because of the insulated glass they come with.
  • Aluminum frames are strong, durable, and resistant to warping, cracking, or swelling, with slim profiles that maximize natural light and unobstructed views.

Selecting the right combination of glass and frame materials depends on a home’s location, exposure, and aesthetic preferences.

When comparing options, smart questions to consider are:

• Does the window meet the standards I need?
• How many laminated layers does the window have?
• Is the glass tempered?
• Who will install the windows, and do they follow manufacturer guidelines and local building codes?
• What kind of maintenance do the windows require?
• Does the window improve thermal performance, noise reduction, and security?

The “best” window is one that performs consistently under extreme conditions while minimizing maintenance, supporting structural integrity, and protecting the resale value.

If you have additional questions (and we hope you do!), let us know. We enjoy educating our clients and guiding them to confident, well-informed decisions about their investment.

For expert inspections, replacements, or installation, contact Garabar at (561) 337-6798.

1. HarperCollins Publishers. (2022). The American Heritage Dictionary entry: fenestration. Ahdictionary.com. https://ahdictionary.com/word/search.html?q=fenestration.
2. ASTM International. (2019, October 15). Standard Test Method for Performance of Exterior Windows, Curtain Walls, Doors, and Impact Protective Systems Impacted by Missile(s) and Exposed to Cyclic Pressure Differentials. Astm.org. https://store.astm.org/e1886-19.html.