As the energy efficient window category matures and the impact/hurricane-resistant category continues to develop, a new breed of high-performance windows is evolving: hybrid windows that combine energy efficiency and impact resistance.
The emerging insulated impact-resistant window category is the result of three developments, according to manufacturers. Impact-resistance codes are being adopted by more states along the Eastern Seaboard up into New England—states with existing energy codes that will still have to be met. Similarly, Southern coastal states from Florida to Texas are beginning to consider implementing energy codes alongside their impact codes; at the same time, snowbirds moving to the South expect to have the energy efficient windows that they've grown used to in other parts of the country. “Most of the hurricane zones are in areas where cooling the home is vital nine months out of the year, so builders are very concerned about combining insulated glazing with impact resistance,” says Joe Herman, vice president of sales and marketing for Hurd Millwork Co.
Even in the Miami-Dade County area of Florida, where impact requirements are most stringent and take priority over energy efficiency, attention is turning to saving energy, according to Dave Koester, Weather Shield's brand manager for LifeGuard products.
Obtaining large windows to show off attractive views will be a challenge, manufacturers indicate, because insulated impact windows use three panes of glass, adding weight and limiting the possible dimensions of individual units.
A heavier window unit also may require special lifting equipment for installation, especially for second-floor applications, says Sarah Meek, trade and channel marketing manager for Andersen Windows and Doors.
Insulated impact-resistant product lines already available include Andersen's Stormwatch-protected windows, Jeld-Wen's vinyl windows with insulated impact-resistant glass, Simonton's Windows' StormBreaker Plus series, LifeGuard Insulated Glass windows from Weather Shield, Hurd's FeelSafe, Insulated Hurricane Impact Products from Vetter, Bryn Mawr II and New Castle XT insulated windows with an impact-resistant option from Certain-Teed, Marvin's StormPlus, Silver Line's SafeGuard double-hung impact-resistant windows, Pella's Architect Series with HurricaneShield glass, Loewen's StormForce IP, and PGT's Vinyl WinGuard.
Because insulated impact-resistant windows are highly engineered to pass impact tests and pressure cycling as well as to reduce heat loss and solar gain, they are more expensive than standard insulated units. Just how much more expensive varies depending on the manufacturer. “Insulated impact products will probably end up two-and-a-half times the cost of a standard insulated window,” estimates Jeff Kibler, brand manager for Vetter.
However, the cost of insulated impact windows is likely to level off and begin to decrease. “I expect the cost will go down as more of them hit the market and as companies continue to refine them,” predicts Stewart.