How Thick Is R-19 Insulation?

Adding insulation to a home can lower heating and cooling costs, benefit the environment and make the home more comfortable to live in by better maintaining the temperature. In addition, adding insulation can improve a home's resale value. The appropriate amount of insulation depends on the type of climate in the home's location. In a cold climate, the United States Department of Energy recommends a minimum of R-49 insulation for attics, while it advises using an R-38 in warmer climates.