Link to the Department of Energy's list of appropriate energy calculators and the IRS' Notice 2006-52.

IRS' Notice 2006-52:
http://www.irs.gov/pub/irs-drop/n-06-52.pdf

Department of Energy's list of appropriate energy calculators:
http://www.eere.energy.gov/buildings/tools_directory/

This Web exclusive information is a supplement to Focus.