To find air leaks, conduct a home-energy audit following the instructions at energystar.gov or hire a pro to do it for $200 and up.
You can cut up to 25% of your heating and cooling costs by adding insulation and using caulk, spray foam and weatherstripping to seal leaks around windows and doors and in attics and basements.
Potential savings: $1,375 in five years, after materials
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