The Energy Policy Act of 2005 (EPACT 2005) incorporates key provisions on energy efficient commercial and residential buildings. The legislation provides tax deductions for commercial construction that exceeds the minimum energy efficient construction standards as required by ASHRAE 90.1, as well as tax credits for highly energy efficient residential construction. 

On the commercial side, EPACT 2005 offers a tax deduction for building owners who make building improvements that reduce energy and power costs by 50 percent over ASHRAE 90.1-2001. While this level of performance is a significant improvement, current insulation, HVAC and lighting technologies can meet this criteria.
 
Specifically, the tax deduction is equal to the cost of energy-efficient improvements installed in a building up to a maximum limit of $1.80 per square foot. To qualify, the energy-efficient commercial building improvements must be installed as part of one or more of the following building systems: interior lighting; heating, cooling, ventilation and hot water; and the building envelope – which includes insulation. (Overview of Commercial Tax Deduction)
 
On the residential side, there is a tax credit of $2,000 for site-built homes that are certified to have a level of annual heating and cooling energy consumption that is a least 50 percent below that of a comparable home constructed in accordance with the 2003 International Energy Conservation Code.  Manufactured homes are eligible for the $2,000 credit in the case of a 50 percent efficiency improvement and $1,000 credit for either a 30 percent improvement or compliance with the ENERGY STAR^® criteria for manufactured homes. (Overview of Residential Tax Credit)