Minimum Attic Insulation R Value
You will need a higher r value of insulation if you live in the northeast than if you live in southern california.
Minimum attic insulation r value. Insulation level are specified by r value. The higher the r value the better the thermal performance of the insulation. There are many ways to retrofit a home with fiberglass and. In zone 2 the average minimum requirement for attic insulation is 9 inches of r30 fill.
The insulation levels of an attic or of any part of a house are understood through the r value that is the value with which the insulating material is resistant to heat flow. For example if you have a type of insulation that has an r value of r 5 per inch of thickness you will need a depth of 6 inches of this insulation installed in your attic to reach r 30 if you live in zones 2 or 3. Houses in a cold climate should have a minimum of r 49 in the attic which is equivalent to approximately 16 of fiberglass insulation. The average recommended level is 17 inches of r60.
How much insulation in attic for zones 1 4. Where you live different climates require different insulation r values. Your home s age if your home is more than 10 year old you likely need more insulation. The table below shows what levels of insulation are cost effective for different climates and.
R value is a measure of insulation s ability to resist heat traveling through it. The average recommended level is 14 inches of r49. In zone 1 the average minimum requirement for attic insulation is 9 inches of r30 fill.