Ya'll know me, I'm big on energy conservation and alternatives and on saving money. Bought this cool book yesterday on insulating and weatherizing your house or apt or condo or whatever you may live in. Here are the stats.
Duct leaks 14%
Windows 19%
Roof 12%
Floor 6%
Air leaks 25%
Walls 21%
Funny how people build a house and do not insulate the walls very well, eh? That one is probably most expensive to redo unless you are building a home from scratch (Which I intend to do, and as green tech as it can get as the VA and Feds give out money to make it green tech).
Duct leaks, easy, get off your butt and go inspect your A/C and heating ducts. Use duct mastic, it is a non-toxic latex based compound that is used to seal holes, cracks, and seams in ductwork and all joints in both supply and return duct systems. Be sure to wear cotton gloves though, fiberglass from insulation hurts! Fiberglass mesh tape is good for reinforcing large gaps and doing structural repairs.
Floor? Forget it unless you are building a custom home.
Roof, another easy one, add more insulation as you wish, they sell blanket rolls at H.D. . Remember, those older houses were built cheap and sold high. More than likely you could use some more insulation.
Windows, I use GILA heat control window film, but that is because I'm in an apt., but if you own a home (Or paying to own I should say if it is not paid off yet), then double paned windows are the way to go, but make sure you get at least a 20 yr warranty, cause once those babies leak, they are shot, they will condense moisture inside and get foggy. Fiberglass frames conduct much less heat than vinyl and wood frames do and is more dimensionally stable. Try to buy low e-coatings that have multiple layers of glass and film that are filled with krypton or argon gas to improve heating performance (This also applies to A/C retention in the summer). More expensive like I said, but you will recover that lost 19% of heat or A/C and thus save on your energy bill, which will pay for the new windows.
Air leaks, weatherstrip your doors well, you can install insulation around your window frame and caulk it up good. Easy way to recover that 14% loss.
I also recommend Energy Star appliances and if you have a manual thermostats, chunk it in the trash (Be careful that it does not have mercury like my old one, I have to take that to the recycling center myself as it is a very hazardous material and I would never just throw it away normally or pour it in the water supply), and go to H.D. and buy a digital energy star thermostat. Check with your local power company also, Austin energy will give you one free and install it, does not get much better than that, eh?
Ceiling fans? Make sure you reverse direction so it is not blowing cold air downward, you want the blades to force air upward so it spreads the heat around.
Fireplace? I love em, and use mine often when cold. You must close the damper when not in use, and why? Leaving it open is the equivalent of leaving a normal size window open, and that's not too bright when the temps are near or below freezing.