Roofing Energy Efficiency Tax Act of 2007 - Amends the Internal Revenue Code to: (1) classify as 20-year property for depreciation purposes any roof system which meets the requirements of Standard 90.1-2004 of the American Society of Heating, Refrigerating, and Air Conditioning Engineers and is on nonresidential real property; and (2) require use of the straight line method for depreciation of such property.