How much insullation should be install. . . How Much Insulation Should Be in an Attic?. So, how should you decide how much insulation to install? The future energy savings, of course, depends upon how much energy costs in the future. 50 per square ft, while it is around $1. thickness of each type of insulation you should . . . 00 . . . . . talk with don't know how much is . . Step-by-step guide to installing attic insulation in a weekend to save energy and . How Much Insulation Should You Have... more