Impact Windows:
Are They Worth the Cost?
Impact windows (hurricane resistant windows) are sold as a great way to protect your home in hurricane-prone areas. The question is, are they able to protect your home and provide an energy effective barrier to the everyday elements?
We recently built a home in northern Florida and installed impact resistant windows.
The owner opted to purchase them from Home Depot as a more affordable, "builder's grade" window versus other impact resistant window options.
Following are photos of two of the windows...one is in the kitchen, and the other is an entry door with impact side windows and transom window.
The experience with the windows has been mixed. First, consider that in many hurricane prone areas of the country, impact window glass could be required by the local building code. In this case, you may not have a choice.
Do You Have Any Other Option?
In our case, we had some options.
Option #1: Custom-cut plywood. This is the cheapest option. In place of using impact windows, the owner could have opted for using plywood as a window covering. (That is, to have custom-cut pieces of plywood for each window to use during a hurricane.) If the owner opted to go this route, we would have had to install a clip system around every window that would allow the owner to quickly and securely install pre-cut pieces of plywood when a hurricane is predicted. This presented several challenges.
One is that the home is seasonal. Therefore, the owner would have to find (and pay) someone to install the plywood. Many of the local folks warn that these folks will charge a premium knowing that a storm is on the way. Then the owner would have to pay them to remove the plywood quickly after the storm so their neighbors wouldn't have to look at the unsightly plywood for months on end.
Storage of these pieces of plywood was another issue. They have to be kept dry and accessible. This would become a real pain considering one was needed for every window and door in the house.
Option #2: The next most expensive option (after plywood): Storm shutters (see the photo below.)
This option would require shutters to be permanently installed on the outside of the window. It may provide an interesting design feature, but it also limits the amount of light that comes in the window. Because we were building such a small home, where we had to maximize space, we couldn't afford to have dark areas (dark = small).
So the owner invested the extra money for the hurricane resistant windows and door glass. So far, there hasn't been a hurricane so we can't comment on actual performance, but we can comment on their thermal efficiency...the owner's experience is that they stink.
When we checked them out on a winter day, the amount of sweating was significant. We have seen super-cheap windows in old mobile homes that don't sweat like these very expensive windows do. With the extreme temperatures in northern Florida, I would definitely do further research into impact windows and more carefully check their thermal efficiency.
The importance of the window's ability to be an efficient temperature control barrier is sometimes understated when considering hurricane protection, but considering the owner's experience with these particular windows (from Home Depot), we recommend thoroughly researching any impact windows' efficiency rating.
