Insulation & air leaks
Adequate insulation reduces the energy consumed by your home's heating and cooling systems.
Insulation makes walls, ceilings, and floors warmer in the winter and cooler in the summer. It plays an integral role in heating and cooling because it allows your home to retain its temperature, which is responsible for as much as 70% of your home's energy use.
There is a wide variety of energy efficient insulation (including water heater insulation) available. Benefits include:
Decreased utility bills (insulation usually pays for itself in a year or two)
Higher home resale value
Better comfort (warmer in winter, cooler in summer) at a lower cost
It is important to insulate not only walls, but the attic, under floors, ceilings, and around basement walls. The best insulation has a high R-value, but the types of insulation needed are different for the various areas of your home, so it is best to consult a professional.
This US Department of Energy tool will give you zip code specific information on insulation: www.ornl.gov/~roofs/Zip/ZipHome.html
US Department of Energy tips on adding insulation to an existing home: www.ornl.gov/sci/roofs+walls/insulation/ins_06.html
Sealing Air Leaks
Caulking, sealing and weather-stripping all seams, cracks, and openings to the outside, will reduce air leaks in your home and reduce your heating and cooling bills.
The US Department of Energy recommends the following steps to seal air leaks in your home:
First, test your home for air tightness. On a windy day, carefully hold a lit incense stick or a smoke pen next to your windows, doors, electrical boxes, plumbing fixtures, electrical outlets, ceiling fixtures, attic hatches, and other locations where there is a possible air path to the outside. If the smoke stream travels horizontally, you have located an air leak that may need caulking, sealing, or weather-stripping.
Caulk and weather-strip doors and windows that leak air.
Caulk and seal air leaks where plumbing, ducting, or electrical wiring penetrates through walls, floors, ceilings, and soffits over cabinets.
Install foam gaskets behind outlet and switch plates on walls.
Look for dirty spots in your insulation, which often indicate holes where air leaks into and out of your house. You can seal the holes with low-expansion spray foam made for this purpose.
Look for dirty spots on your ceiling paint and carpet, which may indicate air leaks at interior wall/ceiling joints and wall/floor joists. These joints can be caulked.