Heating UpHome buyers warm to in-floor heating.

Radiant floor heating just might be the oldest luxury heating technique in history. Roman engineers, faced with the task of heating their enormous bath houses, developed their own floor heating system called the hypocaust: a floor raised on pillars over a hot furnace, creating warm floors and a toasty room.

In modern times the technology of radiant floor heating has changed, with polyester mesh electric heating mats or flexible plastic tubing replacing wood-burning furnaces. But the effect has stayed the same: luxuriously warm floors that heat the room and pamper the body.

Today the technology is growing faster than ever, fueled by advances in materials, concerns over energy costs, and homeowners' desire for spa-like bathrooms that indulge their desire for comfortable surfaces. Owners of heated floors will notice the comforting heat at first, but, as with the sun, the floors become second-nature necessities over time, says Dan Chiles, vice president of marketing for Watts Radiant.

“Homeowners are emotional about their radiant floor,” he says. “They'd rather give up their roofs then their radiant floor.” Watts Radiant offers two different floor heating options for builders and remodelers, with different applications. Electric mats are mostly used for smaller areas and are usually used just for floor warming, rather than as a primary heating source. Because they are quick and easy to install, they are often used for remodeling. Hydronic or hot water heating, on the other hand, is often used throughout a house and can serve as the primary source of heat. Installing the pipes and related infrastructure requires more planning and time, however.

“If [homeowners] want hot water, they have to decide very early on,” says Steven Klenk, vice president of home builder Pinnacle Custom. “The construction of the home almost revolves around whether they want radiant or not.” Klenk says his firm uses both hot water and electric, adding that if the home already has a boiler servicing a baseplate, it makes economic sense to use hot water heating.

More Floors. Both electric and hydronic radiant heating have grown as fast as consumers' interest in recent years. A Radiant Panel Association survey of manufacturers and primary importers found 2005 sales of hydronic tubing at 333 million feet, an increase of about 36 percent since 2003, though virtually flat since 2004. The survey also estimated North American electric radiant panel element sales at 6.2 million nominal square feet in 2005, a 7 percent rate of growth after sales numbers almost tripled in 2004. While growth appeared to level off last year, Larry Drake, executive director of the RPA, says it may just be the result of consolidation in the industry. “Everybody seems to agree that the industry is booming,” he says.

Much of the growth seems to come from a realization among consumers that radiant floor heating is not as expensive as it once was. Manufacturers estimate the average pre-installation cost of a bathroom electric radiant heating system, including programmable thermostat, at around $400 to $700. “Ten years ago people thought of it as something to do if you won the lottery,” says Kevin McElroy, vice president of sales for Nuheat. “Now it's the next necessity.”