You can save 10% or more on your energy bill by reducing the air leaks in your home.
First have your home tested with a blower door. This device can help determine where the air leakage is occurring as well as identify the air tightness of your home. A home that is too tight may need some form of mechanical ventilation.
Seal all thermal bypasses such as plumbing and electrical penetrations, chimney chases, partition walls that are open to the attic or crawlspace, attic hatches, recessed lighting, and soffits over cabinets.
Seal unused fireplaces or keep the damper closed when not in use.
Install double pane, Energy Star rated windows.
Caulk and weatherstrip doors that leak air and install insulated doors if possible.
Be sure that ceilings above dropped ceilings are sealed.
Seal unused chimney flues.
Seal air leakage areas around basements and crawlspaces and sill plates.