According to the U.S. Energy Information Administration, about 40 percent of energy use in the U.S. is residential. What’s more, the U.S. alone is responsible for 18 percent of the entire planet’s energy demands. Are you an energy hog? Reduce your use with the 7 best energy efficiency apps for your home. Once you start getting a clearer picture of how your home functions, we guarantee your next home renovation will include much more strategic efficiency upgrades.