People don't buy windows because they want them but because they need them, Arthur Mullian believes. Usually that need occurs when a new home gets built, and it helps explain why, as the homebuilding market sputtered, demand for windows in dollar terms fell 4.3% per year between 2004 and 2009. But a need to buy also can be spurred by the desire to take advantage of a tax incentive, such as the $1,500 one that the federal government offered last year. "If it wasn't for the federal tax credit, I think a lot of companies would have gone under," says Mullian, owner of Regal Home Improvement Co. in Richmond, Va. "It drove sales in a bad economy."

Today that benefit has dropped to just $200, but the Freedonia Group, a Cleveland-based market researcher, believes window and door demand is on an upward track, climbing since 2009 by 6.6% per year through 2014.

What is making people want to buy a need product? It appears that if the window saves cash on maintenance costs, spares cash by not needing a replacement, conserves cash with reduced utility bills, and collects cash in incentives, it's a sell. And if it comes in a color other than white, tan, or beige, even better. Here are four trends propelling the types of windows you'll see in that 6.6% growth rate.

1. Return on Investment According to the National Association of Home Builders' 2011 Green Remodeling survey, 61% of respondents would spend more than $5,000 upfront to save on utility costs, and 72% say energy efficiency features in a home would influence whether they buy.

In an effort to bring the price down and encourage greater efficiency, the Department of Energy (DOE) recently launched the high performance Windows Volume Purchase program, essentially a marketplace where vendors list fixed prices for minimum orders of 15 retrofit or 20 new windows that meet ultra-efficient R-5 requirements. R-5 translates window-speak for consumers better acquainted with wall insulation measurements and is roughly equivalent to a U-factor (a thermal-transmission measurement) of 0.22 or lower for operating units and 0.20 for fixed, preventing heat loss 30% better than current Energy Star windows, the DOE says.

The ROI on an R-5 varies. Lawrence Berkeley National Laboratory estimates the annual savings of an R-5 window over an Energy Star window is $134 in Boston, $124 in Minneapolis, and $81 in Spokane.

"The tax credit raised the bar on the energy performance of windows and doors, so now the DOE is getting after different ways," says Andersen's manager of corporate affairs, Susan Roeder. "We think that's good, but at the moment, putting the focus on this super, super energy efficient [R-5] window, which is more costly and hasn't yet been proven for longevity, feels a little like the eye off the prize."

The energy efficiency talk has made a significant impact on homeowner awareness in recent years, Milgard product specialist Pat Kopischkie says. "It's been ingrained in peoples' heads. If I'm going to replace my windows or looking at window selections for a new home, certainly energy efficiency comes into play."

Windows such as Ply Gem's R-5 Series, Jeld-Wen's Premium Vinyl line with the Energy Saver Max-K glazing option, and Simonton's Reflections series (circle 153) are several of nearly 200 windows and patio doors in the DOE's program.

2. Room With a View "Even though they're making houses smaller, they're making windows bigger," observes dealer Bart Graves, vice president of John E. Quarles Co. in Fort Worth, Texas. Bigger windows, and more of them, is a trend sweeping the nation from the West Coast and deriving from consumers' desire to use natural light and bring the outdoors in.

"If you look at commercial jobs, these pieces of glass are just astronomically big these days and we're seeing that in residential houses now," Graves says. "It's floor-to-ceiling pieces of glass. I'm doing things now I never dreamed about doing."

Gary Pember, vice president of marketing at Simonton Windows, tags the trend "Small but Mighty" as window area grows with fewer and fewer walls. "You're seeing whole walls dedicated to windows and areas where you didn't have windows before, like bathrooms," Pember says.

The fad spread so fast it took Marvin Windows off guard. In February, it introduced the 40x92-inch Clad Ultimate Glider window, sized to meet most of the large-format orders. But immediately after the product debuted, requests came in for even bigger sizes, says Christine Marvin, the company's group product planning manager.

"When we launched our Lift and Slide Doors, our target was the West Coast, but something unanticipated was the majority of our quoting activity and sales have been in Minnesota and the Midwest–we're not seeing this trend toward larger sizes specific to any certain region," she says.

Windows such as NanaWall Systems' Kitchen Transition and Jeld-Wen's Tilt and Turn Window are built to bear the weight of giant, heavy panes of glass as advancements in architectural support allow greater spans of open space.

Pember predicts the style will stay in vogue for a while: "Even though the square footage is going down for new construction, we expect the number of windows per square foot to go up."

3. Plastic Rainbow Vinyl and Fiberglass windows and doors will take market share from wood and metal units and advance more than 10% per year, Freedonia forecasts.

"It wasn't until vinyl had become a mature product that people then started to say, 'Does it come in any other color than white or beige?'" says Atrium's director of product marketing, Loren Sloane.

Only in the past 18 months has paint and vinyl technology improved so paint will stick and darker colors will not absorb heat and deform the plastic–and do it well enough to carry a warranty. Now dealers say more colors, and darker colors, are in huge demand.

"Those problems have been solved to the point now where we can paint windows darn near any color and are pretty comfortable with it in most parts of the country," Sloane says. Milgard created a powder coat application for its Premier Vinyl Finishes to get it to stick to the slick surface without chipping or fading. Jeld-Wen can custom match any color, including black or dark bronze.

4. Cost of Quality As people opt to stay in their current homes longer and choose to remodel rather than buy, they want quality products that will last as long as they do, says Van Garber, vice president of marketing for the national distributor Norandex.

"Durability is just as high, if not higher, than energy efficiency," Kopischkie finds. "A lot of it has to do with the economy. There's a lot of scrutiny that goes into homeowners' projects. If I'm going to stick money into this I want to know, 'What does the long-term look like?'"

But the quality has to come at a good price. According to a 2010 study by J.D. Power and Associates, price has become increasingly the make-or-break factor for window shopping consumers.

In Virginia, "a window is just a window, so install the cheapest one" is the attitude Mullian hears from customers as he watches them go to franchise window dealers with promises of $165 and $189 units.

"People now have a certain amount of money they can spend and they're very frugal," Mullian says. "Everyone says they want to be green and save the environment, but I think it all boils down to 'What's it going to cost?' You have to have a good product to separate yourself."

The three brands topping J.D. Power's 2010 consumer satisfaction study were Simonton, scoring high for easy operation and durability; Window World, a winner in price and warranty; and Marvin, which did well in ordering and delivery, appearance, and design.

"It used to be we bragged about our Rolexes and extreme purchases. Now we brag about the fact we bought this or that at the discount store," Pember says of the frugal-consumer trend. The focus has changed with the economy revealing the extent a need market needs some want.

"You have to do all the things they want: more choices, personalization, beauty, thermal efficiency, but you have to show them how you're saving them dollars," he says. "It's not the lowest price, it's better value."