Do I Need Impact Windows?

impact windows

Impact Windows and Windstorm Windows: What’s The Difference?

Impact windows and windstorm windows are designed to offer enhanced protection against severe weather conditions, particularly storms and hurricanes, and are required by building codes in coastal areas. To see if your residence requires storm-rated windows, visit this site and enter your address in the search field.

Impact windows are designed to withstand the high winds and flying debris of storms and hurricanes. Made with laminated glass consisting of two layers of tempered glass bonded with a layer of Polyvinyl Butyral (PVB) or Ethylene-vinyl Acetate (EVA), these windows are built to be resilient. They are designed to resist breaking and stay intact even when shattered, providing a consistent barrier against the elements. Here is a missile test demonstrating the stopping power of laminated glass.

Stated simply, windstorm windows are impact windows minus the laminated glass. Any window can be used in a windstorm area if it meets the Design Pressure ratings required by local building codes.

coastal homes in wind storm area

What is Design Pressure?

A window’s Design Pressure (DP) Rating is an essential factor in providing key insights into the strength and performance of a window. It’s an integral part of window specifications and installation, particularly for buildings in regions exposed to high wind speeds and pressures, such as coastal and high-altitude regions.

Design pressure rating is a numerical value that determines the amount of pressure a window can withstand when closed and locked. Manufacturers determine this value through testing standards set by the American Architectural Manufacturers Association (AAMA) and other similar bodies worldwide. The tests involve subjecting the window to positive and negative pressures, simulating wind forces, and assessing performance concerning water penetration and air infiltration.

The importance of appropriate window design pressure cannot be overstated. A correctly rated window protects against weather elements, particularly wind and water resistance. In high wind events like hurricanes, improperly rated windows can potentially fail, causing significant damage to the interior of a building. Additionally, a window that isn’t sufficiently resistant to water penetration can lead to moisture infiltration, potentially causing mold growth and structural damage over time.

Several factors influence the design pressure rating of a window. These include the window’s size, design, and material. The window’s size and shape can impact its structural integrity. Larger windows, for instance, generally require higher DP ratings than smaller ones. The material also plays a crucial role – for example, metal-framed windows often provide better resistance to wind pressure than their vinyl counterparts. Lastly, even the best-designed window may fail to perform effectively if not installed correctly, underscoring the importance of professional installation.

hurricane damage

Additional Benefits of Impact Windows

Beyond storm protection, impact windows offer numerous benefits, from improved energy efficiency to enhanced security. Impact windows are constructed using multiple layers. The primary element is laminated glass, which consists of two glass panes bonded together by a clear, durable plastic film. This design ensures that even if a high-speed object shatters the glass, the plastic interlayer holds the glass fragments together, preventing them from becoming dangerous projectiles.

Notably, the robustness of impact windows goes beyond their ability to withstand strong winds and flying debris. These windows play a significant role in maintaining the structural integrity of a building during a storm. When ordinary windows are breached, the pressure inside the building can increase drastically, leading to roof and structural failures. By resisting breakage, impact windows help preserve the equilibrium of internal and external pressures, thereby protecting the structure of the building.


Impact windows contribute to energy efficiency as well. Their insulating properties help regulate indoor temperatures, keeping homes cooler in the summer and warmer in the winter. This climate control can lead to substantial savings on energy bills, making impact windows a smart long-term investment. Additionally, many impact windows have a low-E coating that blocks harmful UV rays, which can fade and damage interior furnishings over time.


The security advantages of impact windows are often underestimated. The strength and durability that make them resilient to storm damage also make them highly resistant to break-ins. The tough laminated glass and robust framing make it extremely difficult for burglars to penetrate, providing homeowners with additional safety.

Noise Reduction

From a noise reduction perspective, impact windows can dramatically improve the tranquility of your home. The same laminated glass and sealed frames that insulate your home from heat and cold also serve as a barrier against outside noise. This can be particularly advantageous in noisy neighborhoods or homes near busy streets.

In conclusion, the advent and development of impact windows represent a significant stride in architecture and housing safety. With their capability to protect against severe weather, enhance energy efficiency, improve security, and noise reduction, impact windows are a testament to how advanced engineering can intersect with everyday living to create safer and more comfortable spaces.

Who Needs Impact Windows?

As we stated at the beginning of this article, your local municipality will set the requirements for windstorm and impact windows. The DP rating is determined, for the most part, by the proximity to the coast. The rating requirements will vary on a single home based on the location on the house, but an engineer will assist with this.

Zones closest to the shore will also require debris protection, and there are two ways to meet this requirement, with the first being impact-rated glass. Impact glass is very effective but also an expensive upgrade.

impact window shutters

The second option is through impact-rated window coverings such as panels and shutters, which will satisfy the code requirements at a cost significantly lower than impact glass. There are many window covering options; you can find a video here.

You Need An Expert

Impact windows, like any home improvement project, are a big undertaking. At Houston Window Experts, we believe that the greatest asset you can obtain in your project is information. That encapsulates our sales philosophy; we aim to equip our prospective clients with everything they need to make an informed decision and, as our reviews attest, sometimes that means pointing them to solutions that don’t include us.

We also believe that options are your best friend, and we carry over a dozen brands of windows and doors for you to choose from, providing you with the best solution for your particular need. Complete the contact form for your hassle-free consultation. If you’re not in the Houston area, check out The Window Experts for a list of great window companies across the U.S.

We are the Houston Window Experts! Contact us today for a Free Consultation on how we can help with your window needs. You may also call us directly by dialing 832-900-7024.

Our Services include: Replacement Windows Houston, TX metro area. Houston Window Experts is a privately owned and operated company in Houston TX. For more information about us, please write to info [at] or call our Houston office at (832)900-7024. All material is copyright of Houston Window Experts. Houston, TX.