I think you need to make an energy/insulation plan IF your planning to
stay in that house for any considerable period of time. It is not only
time intensive but costly to correct all of your issues. Even so, if
your going to live there 5+ years you can easily get your money back
and then some with the updates. Energy is only going to get more
expensive as the years go by.

For example:
First bring attic insulation up to R30
Replace leaking windows OR buy storm windows. (Personally the windows
work best.)
Make sure there are no leaks/holes in the house (I found three serious
leaks in my home inspection and sealed them with inexpensive thermal
expanding foam)
Investigate wall expanding foam options: http://www.tigerfoam.com/
(this I have not done yet.)
The Walls would be my last choice.
You might see if your electric company offers a "thermal" inspection.
They use a special camera which shows your energy leaks.

best


wrote:
Interesting. I have 1 inch of fiberglass insulatio in the walls, and
several inche sin the attic. Last January my gas bill was $400. I
also have 1949-era single-pane aluminum windows. I think covering the
windows will help but my real probelm (sicne I have no basement - just
a slab) is the walls.