Earlier this year, at the International Builders' Show, Warroad, Minn.–based Marvin Windows and Doors introduced the new operable Ultimate Double Hung Magnum window, which measures a whopping 10 feet high by 5 feet wide. The introduction “is exciting because it's the first wood window to offer incredibly large sizes that perform to commercial standards,” Thomas Goetz, product planner for the company, said in a release announcing the window.

The introduction of such a large window is indeed big news, but what is also significant is that Marvin wasn't the only manufacturer to do so. Medford, Wis.–based Hurd Windows and Doors got in on the act, introducing the Kingsview single-hung, which also measures 10 feet tall.

These product introductions raise an obvious question: Why? Are people really in the market for windows that big? Unquestionably yes, says Rod Clark, windows product marketing manager for Klamath Falls, Ore.–based Jeld-Wen. “There is a serious demand for these products,” he says. “Architecturally, it is in vogue, and I think you will see even bigger sizes.”

It's not surprising that the window is the latest building product that has grown beyond imagination. Even as families are getting smaller, houses are getting larger; windows and doors have caught the bug.

Builders in the Western states first realized that taller doors made spaces feel dramatic and impressive. Then followed large exterior doors, which allowed homeowners to blur the lines between indoors and out.

Now, homeowners want bigger windows to match those doors, and manufacturers are working overtime to oblige. “Home buyers want their exterior openings to match their interior openings,” says Tom Sinning, director of dealer sales at Marvin. “It's for the aesthetics of the building, and the larger window makes the interior appear larger” because it allows light to penetrate deep into the house. People are more comfortable when they are engaged with the outdoors, says Sinning, and having large windows allows them to do that.

George Digman, director of research and development at Kolbe & Kolbe Millwork, in Wausau, Wis., says consumers have always wanted larger sizes, but up until recently they were unable to get them. “If you go back before the '80s, you'd see a lot of larger sizes at the Builders' Show,” Digman says. “But then, all of a sudden, [the trend] moved in the other direction because the energy crisis happened.” A large window with energy-inefficient glass was bad for utility bills, so people were ripping out their larger windows and putting in smaller units, Digman explains. “The pendulum has swung again.”

You can thank innovation for facilitating the trend. In the old days, says Digman, large glass sheets would deform and deflect in the middle, which limited sizes. And weights and pulleys were needed to operate large windows. Today, high-performance, low-E glass, argon gas, and double glazing permit large glass openings, and better hardware allows homeowners to operate them without much strain. Kolbe says that its Sterling double-hung uses a spring balance system, so it is easy to operate. Marvin's Ultimate double-hung has a spiral balance that carries 70 percent of the sash's weight.

Now that manufacturers are able to deliver bigger windows, consumers are asking for even bigger openings, further pushing the limits of what is possible. “Some of the things being requested of manufacturers are more challenging,” Clark says. For example, at the moment Jeld-Wen offers a 7-foot casement window, and that is as big as it can go right now. The hardware just isn't available to move a casement bigger than that—at least not without some problems. If such a large casement is left open, it will put stress on the hardware, Clark explains.

Home buyers in hurricane-prone areas also are asking for bigger units. “There are a lot of large homes going up in coastal areas, so the pressure has been on us to go larger with higher [design pressure] requirements,” Digman says. Plus, these units must also be energy efficient.