I'm planning a large house with high ceilings and lots of windows. Is radiant floor heating practical?

High ceilings and "lots of windows" are one of the main reasons why radiant heat is chosen as a building heating system. Since hot air rises, in a forced air heating system all of the nice, usable heat is first sent to the ceiling. This may be anywhere from 10 to 20 feet up. By the time this air makes its way to your level, about 6-ft. off the ground, it has lost most of its energy and has started to get pushed down by the other hot air entering the room. If this air is cooler than when it entered, where did all of its heat go? Right out the ceiling. Radiant heating works in just the opposite way. Since a radiant heat system stores its energy in the floor, all of the room's warmth is kept right where it needs to be, on the floor where you are. The ceiling in a radiant floor system is always much cooler than the floor area, just the way you would want it. This cooler ceiling temperature means less energy is being wasted to the outside. Less waste means higher efficiency.  more