The insulation in your home’s walls is not made of cotton (it is probably made out of fiberglass), but it works much the same way.

You may be surprised to learn that many homes are poorly insulated —they have too little insulation (or maybe none at all!) in their walls and ceilings to effectively slow down the movement of heat from inside to outside. Because of this, their owners must burn more fuel in order to stay warm. This is a major cause of energy wastage.