That depends on four things: the recommended R-value, your climate, the type of heating and cooling system you have, and the section of the house you plan to insulate. For the recommended levels of insulation, the U.S. Department of Energy publishes this map with the R-values they recommend. Once you know your R-value, use our blow-in insulation calculator to find out how much Greenfiber insulation you’ll need. Just enter the dimensions of your space, and we’ll give you an estimate of the materials required to get the job done.