### Question
How is the term energy efficient commercial building property defined?


### Answer
The term **energy efficient commercial building property** is defined in *26 U.S.C. § 179D* as the following:

> property—


(A) with respect to which depreciation (or amortization in lieu of depreciation) is allowable,


(B) which is installed on or in any building which is—


(i) located in the United States, and


(ii) within the scope of Standard 90.1–2001,


  

(C) which is installed as part of—


(i) the interior lighting systems,


(ii) the heating, cooling, ventilation, and hot water systems, or


(iii) the building envelope, and


  

(D) which is certified in accordance with subsection (d)(6) as being installed as part of a plan designed to reduce the total annual energy and power costs with respect to the interior lighting systems, heating, cooling, ventilation, and hot water systems of the building by 50 percent or more in comparison to a reference building which meets the minimum requirements of Standard 90.1–2001 using methods of calculation under subsection (d)(2)

#### Citation:
  - *26 U.S.C. § 179D*
  - Heading: **Subtitle A-Income Taxes > CHAPTER 1-NORMAL TAXES AND SURTAXES > Subchapter B-Computation of Taxable Income > PART VI-ITEMIZED DEDUCTIONS FOR INDIVIDUALS AND CORPORATIONS**

