One of the easiest and most informative ways to gain expertise in green building design is to start using the various green building design tools available online- many are free.  These tools include calculators to evaluate roof insulation, reflectivity, life-cycle cost and daylighting, as an example. These tools can be especially useful as a first step toward developing cost-effective sustainable roofing strategies.

NRCA's EnergyWise Roof Calculator Online, which was developed by NRCA and the Polyisocyanurate Insulation Manufacturer's Association, is a Web-based application that allows users to construct virtual roof assemblies to evaluate thermal efficiency and estimate energy costs via comparison with other roof assemblies.  Additionally, the calculator can help users estimate the potential savings a building owner can realize by installing additional insulation beyond specified building code minimum levels.

The U.S. Department of Energy's Cool Roof Calculator was developed by Oak Ridge National Laboratory, Oak Ridge, Tenn., to help building designers estimate the effects of roof reflectivity for buildings with low-sloped roof systems.  using this Web-based tool, you quickly can compare the energy cost differences of reflective and non-reflective roof systems in more than 200 cities.

The GreenSave Calculator, sponsored by Green Roofs for Healthy Cities, let you compare roofing alternatives during a specific time period to determine which has the lowest life-cycle cost.  using this tool, you can determine whether higher initial costs are justified by reducing future operating, maintenance and repair costs or by producing other benefits, such as energy savings.