Roof Calculators

There are a variety of tools available to estimate the cost savings of the proper specification of insulation and membrane surfacings available on the web. These tools look at the annual cost savings based on your specified roofing system to help prepare return on investment (ROI) strategies and to justify the initial capital expenses associated with the increased energy performance. The following calculators are listed based on complexity and the amount on information required to provide saving estimates (Least complex first):

1. The ENERGY STAR's® Roof Comparison Calculator estimates annual energy savings for typical building types with non-metallic-surfaced roofs using typical weather conditions. These estimates are derived based on simulations run with the DOE-2.1E model using cooling and heating degree-days.
   http://www.roofcalc.com/RoofCalcBuildingInput.aspx
2. The DOE's Cool Roof Calculator was developed by the U.S. Department of Energy's Oak Ridge National Laboratory. The calculations require more input data and there are 243 different locations built into the pull-down lists in the calculator; 235 for the US, Pacific territories and Puerto Rico; and 8 Canadian cities. There are two calculators based on building the following facility size:
   For large facilities (Version 2.0):
   www.ornl.gov/sci/roofs%2Bwalls/facts/CoolCalcPeak.htm
   For small and medium-sized facilities (Version 1.2):
   www.ornl.gov/sci/roofs%2Bwalls/facts/CoolCalcEnergy.htm
   
3. In addition to the above energy calculators, many trade associations like the National Roofing Contractors Association (NRCA) have their own online calculator to help in the specification and design of an energy efficient roofing system.
   http://energywise.specright.net/