Whats new - we have completed installing the under floor insulation. This product is called Foilboard it hangs between the joists below the floor level by about 25mm and is a foil coated product both sides. Once sealed and taped up and having the board on top.
The warmth in winter will stay mostly in the house and not have to deal with the heat loss into the subfloor. Besides looks great at the moment all bling.
If you were renovating you could fit this product to an existing house.