How much insulation is needed to build a room?

When you build a room onto an existing home, insulation is tricky to figure out. It will depend upon the climate where you live, as well as the local building codes for your particular area. Insulation is based on R-value, which is its value to heat resistance and flow. An R-value is placed on all insulation, and will give you the specifics for its use and areas on the label. You need to insulate the ceiling and walls that face the exterior. You will not need to insulate under the room, as you need air flow in the crawl space below. Consult a representative at your local home improvement store to assure that you have the correct type of insulation, which will then be easy to install on your own.