Allowing more natural light into a house and mixing the outdoors with indoor living space are two of the strongest trends in home design. So it's no wonder that sunrooms like the Frye's are receiving a warm welcome from homeowners across the U.S. Adding a sunroom has become the fifth-most-popular remodeling project, according to the National Association of the Remodeling Industry.

If you're shopping for a glassed-in room today, you'll find the terms conservatory, solarium and sunroom used almost interchangeably. However, makers of higher-priced, more rococo structures generally prefer conservatory. What they all imply, though, is not glassed-in porches or decks livable when the temperature allows, but insulated rooms that are livable year-round.

The Fryes bought their 54-square-foot mahogany-and-glass sunroom addition from Tanglewood Conservatories, a company on Maryland 's Eastern Shore . They use the sunny space every day as their dining room. "In this area, you can't be outside comfortably much more than six or seven months a year. In those months that you're cooped up in the house, it helps to bring the outdoors in."

In most locales though, keeping the sunroom comfortable on hot, sunny days is the greater challenge. Placement is one of the keys and so is the use of high performance glass. A room will best capture the sun if it's on a house's south side; but you have to properly prepare for it. When John Salvatore was building a custom home near Newport , California , his architect and builder tried to warn him against building an all-glass conservatory on the house's west side. "They were concerned that it would really get hot and uncomfortable, and the energy bills would go through the roof", Salvatore recalls. But he insisted, and he hired Tanglewood Conservatories to design and install a 16 foot by 18 foot conservatory off the kitchen.

The conservatory uses special high-efficiency glass, has its own heating and air-conditioning system, and also has vents in the roof that open automatically when the air gets too warm. In late September, Salvatore filed a weather report from the conservatory which at the time wasn't using extra air-conditioning: "Today we had 102-degree weather, but the conservatory stayed relatively cool".

One last thing to remember: somebody has to clean the windows. "Washing the windows is a little bit tricky," notes Salvatore . He recommends sticking with professional window cleaners, who can use telescoping poles and a power washer to leave the roof and walls spotless. Salvatore recently paid a commercial window washer $250 to clean the inside and outside of all 27 glass panels in the sunroom. "I think twice a year is plenty," he says.

Adapted from"Room with a View", by Elizabeth Razzi, Kiplinger's Personal Finance