[stags]

Darin, I agree with CDJr on the air infiltration. I always insist that people address this first before adding insulation, especially in walls. I know you said your attic has insulation but check to see if there are gaps or voids around lighting fixtures, chimneys, bathroom fans etc. Wire/plumbing runs can be sealed with spray foam, larger gaps can be filled with fiberglass batt. Do the same thing in your basement, garage, exterior. Seal around the switches/outlets on exterior walls and around your attic access door. Also check for drafts around exterior doors. Your attic should feel very cold in this weather. If not, you may need to add insulation there also but def. address the air infiltration first. Let me know if you need any supplies although all this stuff is available at the big box stores .

[sdbob]

You didn't say howmuch,thick insulation you ahd in the attic? I'm adding another 12" of fibreglas to mine right now. I always told are customers that energy prices will always go up,plan for better insulation.Bob

[Pearlbluebird]

Darin, there are a few options for you. The best but most expensive way would be to have Icynene foam injected into the walls. This will both seal all air leakage and have a higher R-valve in a 2x4 cavity. The plug holes are very small and won't be noticeable after.
You could just go for blown in insulation which would be suffient, but I would continue to air seal the rest of the wall after. I would call an insulation contractor for a price and method of how they are going to proceed with the work.
You will see more savings if this was done before the windows. Considering there price.