Properly insulating your home, including sealing drafts around windows and doors, can save you 10 to 20 percent on yearly utility costs.
But how do you judge how well your home is insulated? Since insulation can deteriorate over time, a home that was once well-insulated may no longer have optimum protection.
One check homeowners can do themselves is to go up in the attic and visually inspect the exposed insulation. A typical unfinished attic will have loose insulation piled on the attic floor as the main barrier to heat loss. These materials settle over time, and that's generally a good thing because the protection is better as the insulation becomes more compact. However, one rule of thumb is that if you can see the floor joists, you no longer have enough insulation to do the job.
Although attic insulation essential because heat rises, you also need adequate protection in walls, crawl spaces and basements. These can be much more difficult to inspect on your own.
For the best assessment, consider having an energy audit in which infrared technology can detect gaps in insulation within exterior walls.