If the roof is not being replaced for other reasons it is typically not cost effective to add insulation.
Savings due to roof insulation.
Net savings ft per year cooling savings ft per year heating savings heating penalty if negative ft per year insulation in black roof to yield same annual energy savings.
Insulation savings calculator use this insulation savings calculator to measure the financial impact of increasing your insulation performance.
In order to get a reasonable answer one must do some testing and compare to the energy used by the house with local weather.
Knowing the r values before and after an insulation upgrade and the average temperature difference across the insulation you can calculate the amount that the insulation upgrade reduces heat flow.
According to the epa you can expect net annual savings of just under 50 cents per square foot of roof.
Upgrade from r to r h ft f btu details of comparison.
Epa estimates that homeowners can save an average of 15 on heating and cooling costs or an average of 11 on total energy costs by air sealing their homes and adding insulation in attics floors over crawl spaces and accessible basement rim joists.
Square feet of house or area to be insulated current and desired r value for insulation and type and cost of your energy.
Enter your data into the fields where indicated.
Knowing the cost of energy and the cost of the insulation upgrade you can calculate the rate of return on your investment in insulation.
The savings and payback vary substantially depending on the existing level of insulation but are typically between 5 20 years.