Source 2015: D+R International in support of ENERGY STAR®. Savings estimates are based RESFEN 6.0 modeling of 8 home profiles across 93 U.S. cities. Home profiles include new construction or existing construction, single-story (1,700 square feet) or two-story (2,600 square feet), and natural gas or electric heating. Savings estimates for each city represent the average of the 8 home profiles in that city. Climate zone savings estimates represent the average savings among the cities in each climate zone. Cost savings calculations used 2013-2014 average natural gas prices and 2012-2013 average electricity prices for each state from the Energy Information Administration (EIA). Actual savings will vary by local climatic conditions, utility rates, and individual home characteristics. Hawaii was excluded from this analysis, as the assumptions in RESFEN 6.0 diverge significantly from the norm in Hawaii. Savings for all climate zones are for whole-home replacement with ENERGY STAR Version 6.0 windows.