In my limited view of the world, I always see old houses as a challenge to see how much insulation I can get into a given wall or roof.

Reality is quite different. There are still many houses with little to no insulation. Whenever I see these houses, I wonder what the owners are waiting for.

The minimum energy code is R-19 for walls and R-38 for ceilings. (Remember, the bigger the number, the better the insulation.) It is hard to insulate the walls in many older homes properly, since the walls are built with 2-by-4s. If you blow in or fit in fiberglass or cellulose into a 2-by-4 cavity, you only get a woeful R-11.

There are some ways to work around this limitation. First, if you have opened up the wall cavity, you can cut and fit sheet foam or spray foam into that 31/2- to 4-inch-deep area. That bumps the wall up to between R-24 and R-30. You can then cover the wall with another layer of foam on the inside before you install drywall. Then the wall goes up another R-7 or more. This extra layer also minimizes the thermal bridging of the studs. When you install foam on the inside, you need to move the electric outlets in the appropriate distance. This is doable and not too annoying.

If the walls are already insulated, you can still make them better. A layer of foam can be applied on the exterior walls of a given room. You would remove the trim and install foam over the existing plaster or drywall. You can then install new drywall over the foam and install new trim. The electric outlets also need to be extended.

There is a little trickery required in installing new trim. Let’s say you put 2 inches of foam over an existing wall and then cover that with half-inch drywall. If you have plaster on the old wall, you are now more than 3 inches away from something to nail your trim onto. You can use long finishing nails to get this done. I also use construction adhesive and some shorter finish nails that are toe- nailed in to help hold the trim in place until the adhesive can bond.

Traditional finish carpenters might roll their eyes, but in my book, if it looks good and doesn’t fall off in normal use, it’s good.

Another option is to install foam on the exterior of the building when re-siding. Here at least 11/2 inches of foam is the minimum that should be installed. Anything lower than that might cause condensation troubles in the wall.

If you have no insulation in your attic, it is time to atone for your energy sins. You need to get this done before this winter. Do it now.

An unused attic that has a flat ceiling is simple to insulate, inexpensive to do and will pay for itself in less than a year.

If you have a floored-over area with fiberglass underneath it, put foam on top of the floor to get up to R-40 and then put some OSB or plywood over it so you can still have your storage.

Be sure to seal up the attic entry with weather-stripping. Check for any holes that open into the attic from the living space. Plug these holes. This is where heat – and your money – escapes.

Once a house has some nominal insulation, a real heat loss area is the basement. That area above grade, the part that sees outside air, is where much of the heat loss is. Insulate this area with fiberglass, foam or anything else you think appropriate. (No bubble wrap!)

Now, you can almost laugh at high heating costs.

Questions for Tom Gocze should be sent to homefront@bangordailynews.net or mailed to The Home Page, Bangor Daily News, P.O. Box 1329, Bangor 04402-1329. A library of his practical home-improvement videos, reference material and a home-project blog are at www.bangordailynews.com/thehomepage.