How do I insulate a concrete floor

[dchopp]

I have a brick built room in the garden with a concrete floor. There is PVC flooring on the floor but however much you heat the room your feet get cold.
To try and remedy this I have considered laying some form of insulation on the concrete with a thin panel of MDF board followed by re-laying the PVC. I did not wish to use carpet.

Is this an acceptable solution and can somebody help on advising the type of insulation material

Thanks

[Perry525]

The best way is to, use a self leveling compound to get a level floor, then to lay Styrofoam over, followed by two layers of 9mm ply overlapped and glued.
This will give you a warm strong floor.
You will probably need to raise the door frame and door, or risk bumping someones head.