On August 8, 2005, history was made when President George W. Bush signed H.R. 6, the Energy Policy Act of 2005. The legislation set a precedent by containing a market transformation incentive in the form of a tax deduction for owner investments in commercial building energy efficiency.

The Energy Policy Act of 2005 establishes a new deduction for expenses incurred for energy-efficient commercial building property. The deduction is equal to energy-efficient commercial building property expenditures made by the taxpayer, subject to a cap. This document describes the tax deduction provision in general. Nothing in this material should be construed as a substitute for consultation with a qualified tax professional.

While this was passed in 05' only recently did the IRS finalize the guidelines, etc. so that it could be used. Here is a good web site for more information:
http://www.efficientbuildings.org/about_the_provision.h
tml

I'm glad that commercial buildings are finally being rewarded with tax credits. For more information on non-commercial tax credits, check out the Greeniacs Guide to tax credits:

http://www.greeniacs.com/GreeniacsArticles/Taxes-How-Be
ing-Eco-Friendly-Can-Pay-Off-For-You.html