How to insulate a suspended concrete floor? On top or below?

[Ali81]

I have a 3 bedroom bungalow with suspended concrete floors throughout, with no insulation below or on top of the concrete. What's the best solutions? The only one I have read about is insulating on top of the concrete with boards on top and raising the floor coverings. (Crawlspace under floor is about 3 or 4 ft, though access is through a 2ft wide hatch)

The concrete floor has tiles on top throughout, which we plan to get taken up as they contain asbestos. It would seem that's the ideal time to do the insulation if it has to be on top.

Any ideas or alternatives?

 

[Why Not Indeed]

If insulating above the floor, you have to think about how much height you can afford to lose. It could be a nightmare, chopping the bottoms off doors, relocating sockets, etc.
Insulating below - this will be much less disruptive, but might not be effective. If there's no thermal break between the concrete floor and the rest of the structure then heat is just going flow out into the structure.

 

[Ali81]

Has anyone had any success with putting the thin multifoil insulation under underlay and laminate or carpet, and it making a difference?