When creating a plan to reduce household expenses on energy, it is crucial to see where most of your energy dollars are going. According to the 2007 Buildings energy Data Book we see the hugest chunk of money spent on household energy goes to space heating, around 31%. 
When planning your household usage energy audit you should be sure to:
• Check insulation in attic, basement walls and exterior walls, floors, ceilings and all those crawl spaces which can lose a lot of heat if not properly insulated.
• Inspect in your walls, windows, ceilings, doors, lights fixtures, plumbing fixtures and even electrical outlets, for cracks and/or holes which can leak your expensive warm air out into the cold, cruel world.
• Are your fireplace dampers open?
• Look for ways to conserve energy use for lighting. Perhaps using occupancy sensors, dimmers and/or timers can help save electricity. Replacing incandescent lights with compact or standard fluorescent bulbs could save you a bundle.

It takes a lot of
. Good insulation should effectively keep either heat or cold, in or out of your house, depending on the weather (season). The most important places to insulate are the space between the doors and the door frames, around the windows, the attic floor or the roof, crawl spaces, and any other place where the outside air can get in and the inside air can get out.