The U.S. Department of Energy's (DOE’s) Building Energy Codes Program has developed and established a methodology for evaluating the energy and economic performance of residential energy codes. This methodology serves two primary purposes. First, as DOE participates in the consensus processes of the International Code Council, the methodology described herein will be used by DOE to ensure that its proposals are both energy efficient and cost effective. Second, when a new version of the International Energy Conservation Code is published, DOE will evaluate the new code as a whole to establish expected energy savings and cost effectiveness, which will help states and local jurisdictions interested in adopting the new codes. DOE’s measure of cost-effectiveness balances longer-term energy savings against additions to initial costs through a life-cycle cost perspective.