R-value measures thermal resistance, the ability of insulation to prevent heat from escaping through the walls and roof of your home. The higher the R-value, the more effective the insulation will be — but your optimum R-value depends on where you live. Basically, the colder the climate, the higher the R-value.
To find out the minimum R-Values* for different areas of your home that will qualify you for energy efficiency tax credits, simply select the state and county where you live. The Insulation Calculator will do the rest — and even suggest CertainTeed insulation products designed specifically for attics, walls, floors and ceilings, and basements.
Click on the link below to visit the Certainteed Calculator.
http://ic.certainteed.com/EN/Index.asp