If there is a space under the floor (which is not part of the house), it is especially important to insulate underneath the floor. This is often the case with ground floor rooms.
The existence of space under the floor can be observed by noticing a grille, as shown in the picture on the right. Such grilles are installed to prevent damp by allowing air to circulate under the floor. However the circulating air also cools the floor. If there is no space under the ground floor, insulation can be installed underneath it but then the floor has to be excavated first. |