I would suggest starting by understanding where you are wasting energy. There are a number of ways to do this.
The best way, if you can afford it, is to get a home energy audit. A professional energy specialist comes to your home and does an assessment of your heating and air conditioning equipment, insulation, wall types, and other factors that can be visually judged to affect your energy costs.
They may then do what's called a blower door test to look for air leaks. This is a very useful step. They open an outside door and temporarily install a thick plastic seal on it, in which there is just an opening for a powerful fan. There are two pressure gauges, one to measure outdoor air pressure and one to measure indoor air pressure. They crank up the fan which sucks air out of your house. This process is harmless (to your house, to your door, to yourself). There are two types of information they derive from a blower door test.
1. They can tell, from the pressure differential between the inside and outside air pressures, how much air leakage you have in your house. This is usually expressed on your audit report as a square. So on my first energy audit I was told I had air leakage equivalent to a 14×14 inch square.
2. They walk around the house feeling baseboards, cracks in the walls, frames around windows, the windows themselves, attic openings, doors, and anywhere else that air leakage is likely to occur. Because so much air is being sucked out the door by the blower, they can feel air being sucked in any cracks. For instance, in my house it turned out that there was air coming in under and above the wooden baseboards throughout my house, and under the quarter-round at the base of the baseboards. There was also lots of leakage around my old windows.
An energy auditor may also look at your electrical usage such as lights, refrigerator/freezer, stove, washer/dryer, other appliances, and note the energy efficiency of each based on age, model, proper installation and other factors.
Usually the auditor will give you a verbal report outlining the major findings, as well as a written report which is generally provided several days or weeks later. The report will recommend changes and identify the benefit of each change, and perhaps the estimated cost. Many auditors will either sell you their services to carry out some of the recommended changes, or will provide references to contractors who can.
The second part of the audit is the follow-up assessment. This is usually done on your schedule: you invite the auditor back to do a second assessment of your home, after you've made the changes you thought most worthwhile or affordable. Each of your assessments may come with a numerical score, and you should see how much improvement your changes made. They also both come with that square of air leakage, so you learn how much you reduced that. In my case, we reduced the air leakage from a 14×14 inch square to a 6×6 inch square by:
– Injecting Icynene, a foam insulation, into the 1-1/2 inch air space between the bricks and plaster of our downstairs walls
– Using clear silicon caulking (Alex Plus I think) on hardwood trim, and white silicon caulking on painted trim, to seal all baseboards, quarter round, window and door frames so that no air could pass through the wall via trim
– Patching cracks in the upstairs ceiling, where air was coming in from the attic
– Properly sealing the attic trap door
– Replacing our remaining 80-year-old windows with new energy efficient windows.
The cost of a home energy audit is probably around $250 these days. When I had mine done in about 2000 I paid $100 but it was also subsidized by the Canadian government.
Check the tax or energy efficiency laws and public utility conservation incentives in the area you live. You may be eligible for energy saving grants or tax credits for any improvements you do to increase energy efficiency, provided they were done as part of a home energy audit program. For the upgrades I did on our home, I got about $200 back as a rebate from my gas utility, and about $700 back from the Canadian government.
If you can't afford a home energy audit or can't find a home energy auditor, or you are just more of a do-it-yourself person, you can do your own mini home energy audit. You probably won't be able to take advantage of certain financial incentives unless you do the professional audit, but if you're only able to afford little changes this may be a suitable option.
I have a little website on home energy efficiency that might be of help. I've provided links below to two particularly relevant pages for you: My home energy checklist, which might give you some ideas for where to look for savings, and my main page on saving electricity, in case that's an area where you're hoping to make your home more efficient.