Due to the variety of building insulation materials available and the various building elements that may require insulation, there are a number of ways of installing building insulation.
Where to insulate depends on where your living or conditioned space (the space that you heat and air-condition) ends and where your unconditioned space begins. Treat unconditioned space as if it were outdoors, minus the rain and snow. Insulate the living space as if you were insulating from the outdoors.
If you occasionally want to heat only some sections of the living space, you should insulate the walls between the sections you want to heat and the sections you don’t want to heat.
There is no harm done in insulating both the ceiling, and the floor and walls.
Due to the variety of building insulation materials available and the various building elements that may require insulation, there are a number of ways of installing building insulation.