Under floor heating is not a new concept in this country either. In the past electric heating elements were buried within floor screeds. These were heated over night using cheap rate electricity.
            
Bedford Plumbing Co puts the heat in the floor under your feet, gently warming a room or a complete structure. This results in similar heating levels with superior comfort without wasting energy and money in monthly fuel bills.

The warm water circulated through the tubing in a radiant floor may come from solar collectors
        
The main fault was the uncontrollability, the building would over heat during the day but in the evening, when heat is generally required, no further heat was available.