Begin by focusing on those small cracks and crevices around doors and windows. According to Lowe’s, a 1/8″ space between a standard exterior door and its threshold is equivalent to a two square inch hole in the wall. Close those gaps to save up to 15% in heating and cooling costs and also reduce the demand on your heating and cooling system. Other energy efficient steps: lower your water heater’s thermostat setting; blanket or insulate the water heater to reduce the amount of heat lost by the unit, particularly if it is located in an unheated area; insulate water pipes, at least the hot water pipes to prevent heat lost that can cause your water heater to work harder; change furnace filters to prevent reduced airflow through the heating/cooling system and overheating that can lead to premature compressor damage in the A/C systems; and install water-saving shower heads.