These analyses evaluate the cost-effectiveness of the prescriptive path of the 2015 edition of the International Energy Conservation Code (IECC), relative to the 2012 and 2009 IECC for all 50 states and the District of Columbia. The analysis covers one- and two-family dwelling units, town-homes, and low-rise multifamily residential buildings covered by the residential provisions of the 2015 IECC.

The purpose of this analysis is to examine the cost-effectiveness of the 2013 edition of ANSI/ASHRAE/IES1 Standard 90.1 (ANSI/ASHRAE/IES 2013). PNNL analyzed the cost-effectiveness of changes in Standard 90.1 from 90.1-2010 to 90.1-2013, as applied in commercial buildings for each state in the United States.