Windows and window systems continue to evolve. Besides controlling light penetration and reducing heat loss, the new generation of windows aims to withstand gale-force winds, filter unwanted sound, and take maintenance to a whole new level, to the point where the windows actually clean themselves.

Impact resistance

The extensive damage caused by Hurricane Andrew in 1992 led to revised code restrictions in South Florida. Because windows that burst or blew out led to much of the storm's damage, codes were rewritten to require structurally stronger windows with glass that resists shattering.

One result was impact-resistant windows, which are engineered to resist wind force and the impact of flying debris. Typically, the glazing in these units is a laminated glass composite. The glass is secured to the window frame with high-strength structural silicone, and installation typically requires double the usual number of fastening screws to secure the window frame to the structure. Added to those safeguards are heavy-duty sashes and frames, as well as upgraded hardware components. "Your installation tolerances are much tighter now," says Ray Reinhard, co-owner of HBS, a Vero Beach, Fla., window and door distributor. Tighter tolerances also enable windows to resist high levels of water infiltration.

Reinhard points out that such units generally cost 40% more than standard windows, but, he adds, "we're seeing that start to come down."

In the meantime, most major industry manufacturers have introduced their own versions of impact-resistant windows, and demand for these products has become widespread in coastal areas from Texas to Maine.

Sound out

Soundproof glass has been available for years but, being anywhere from 1 to 4 inches thick, hardly has been practical for residential use. That's changed. Today's soundproof windows are popular in cities and other heavily trafficked areas. As with impact-resistant windows, innovations center on both product design and glazing technology.

Most often, soundproof windows are designed with two panes of glass -- a thick pane on the outside and a thinner pane on the inside. Gas between the panes, as well as a layer of plastic to inhibit glass vibration, acts to filter sound. Soundproof windows also feature a laminated coating applied to the glass surface. Manufacturers claim this acoustical engineering can reduce the penetration of outside noise by 75% to 90%.

Self-cleaning

Introduced in this country in 2001 by two separate manufacturers, self-cleaning glass features a coating -- titanium dioxide -- that interacts with ultraviolet light to break down dirt and organic matter.

Lisa Detweiler, of PPG, one of those manufacturers, calls it "a totally new category." The glazing, now included in the product lines of at least 23 window and sunroom companies, enables homeowners to clean their windows simply by rinsing dirt off with a garden hose. Windows featuring self-cleaning glass usually bring a 20% premium on the market.

Ray Westmoreland, owner of Wood Windows in Boise, Idaho, says that while the product is available to him through distributors, "we haven't yet sold an order for self-cleaning glass." Westmoreland says he expects tremendous interest from consumers as word gets out.

Ken Olinger, president of Amazing Siding Corp. of Portland, in Vancouver, Wash., says widespread promotion of the product has expanded windows from 10% to 30% of his company's sales. He expects self-cleaning windows to get popular fast.

Westmoreland is more skeptical, especially when it comes to guarantees. "What if you run into a jerk for a customer?" he asks. "You might be out there washing his windows."