[rjacob]

One of the biggest engery wasters in houses is leaks. Most houses are very leaky. The older your house, the more leaky it is likely to be. The cost of sealing is pretty low, but it can be time consuming.

The mian expenses are things like silicone caulk, expanding foam, insulation, etc.

I pulled off the trim around all my windows and doors, and sealed between the frame and drywall. I sealed around all the outlets. I replaced some of the seals in doors and windows. I went around the outside of the house and seal under the siding where it overhangs the foundation. Around pipes and cables entering the house. Anywhere I thought air might be coming in or going out.

I had had a blower door test before and after, and manage to reduce the leaks by about 1/3rd. I have done sealing since then.

I have also done stuff like programmable thermostats, CFL lighting almost completely through the house, motion senser lights in the garage (this can be a little annoying when are out of their line of sight). I also insulated a kneewall. All these things add up.

But the air sealing of the house has made the biggest impact to our energy costs. And it really didn't cost a lot of money to do it.