By designing effective ways to insulate your home, of course! In total, 48% of the energy used annually in the U.S. is spent on heating buildings during the colder seasons and keeping them cooled during the warmer seasons. Insulation materials help to maintain the temperature differences inside and outside of buildings. In addition to polystyrene and other types of insulation, materials to seal window panes and other potential leaks can significantly reduce the amount of energy we need to spend on heating and cooling.