Underfloor heating can be a most economical and efficient way to heat your home. It can be used to supplement your existing central heating system, or it can replace it outright if you install it in every room that you want heated.
There are two main types of underfloor heating (UFH) available, wet and dry; the wet system uses hot water pipes under the floor and the dry types use electric heating elements, these take the form of has an open- weave mesh, connected to a thermostat and the mains. The wet system would be connected to your existing central heating system and uses continuous plastic water pipes. These have no joints so are guaranteed not to leak and should require no maintenance.
The heat from either system is emitted in a gentle, pleasant way that is more energy efficient and heats a room far more evenly than any other type of heating available. You will have no cold or hot spots in the room and no longer need to have any radiators on your walls. It is ideal for rooms with hard flooring and can be installed under any type of surface, but can be tricky to install sometimes, depending on the type of floor and heating system.
Overall, underfloor heating is best suited to being installed under solid floor surfaces and should be considered at the same time as planning a new floor covering. The main expensive involved in installing UFH is the installation itself as the floor level may have to be changed (more so in the case of a wet system as the electric system is much thinner) and it may require some excavation but no more so than when installing a solid floor anyway.
You would need to consult the company that is supplying the system if it is to be connected to your boiler, whether the boiler has the capacity to feed the system, or is even compatible. There will certainly be limitations to how many rooms you can heat this way with a wet system and these would depend on variables such as the size of the rooms, the ceiling height and the heat retaining properties of each room, which would mean how well insulated it is. With either system there has to be a layer of highly efficient insulation installed below the heating elements or water pipes so that the heat is projected upwards, otherwise it would be wasted heating the ground below.
With any wet UFH system, each room would have its own control and timer unit and these systems are overall more expensive to install but cost the least to run. The electric systems are cheaper and simpler to install, require less in the way of modification to your floor but are more expensive to run. The most economical option is when used under a solid floor and run on economy 7 tariff. The solid floor will act like a storage heater and the stone or tile will warm up overnight and release the heat gradually throughout the day and you would have the option of topping up at any time if needed for a heat boost later in the evening.