Also replace your light bulbs with CFLs now. They may seem expensive at first, but I am 4 years into my house and haven't had to replace a light bulb since moving in. And the bulbs have gotten better in the past 4 years. The have a much softer, more natural light and don't require that annoying warm up time anymore.

If you are unsure what to do about the wall insulation, see if any contractors offer thermal imaging. They can come out with a thermal camera, take pictures and literally show you the insulation "holes" in the walls without removing anything. Then you can plan what is the best approach. You may just have some spots were insulation has dropped. It may be fine.

That was a bit long winded, but I hope it helps!

To understand what to do is simple.

Start with your attic.

Look around the attic, pull insulation up in various areas and take a look see if it appears to be blackened from dust. This means there is air flow that is robbing the R value out of what is already there. In that same area you most likely will find, openings from wires coming into the attic from below, ceiling boxes that support lights below, Access doors that are poorly sealed. Perhaps pipes from baths and kitchens below. All should be sealed. Do you have can lights that stick up into the attic? These are big energy loss hogs.

Get a few cans of spray foam. With the exception of the can lights, Foam around all of these openings. If you see the top plates of the room below that crisscross in the attic, seal those edges as well. There should be no openings left alone.

Why? Air as it exits the living area into the attic through these holes will pull the conditioned air out of the house. Much like a sweater you wear it feels warm until a breeze blows. That chill you feel is the heat being drawn out of the material. Same thing happens in the attic.

The next thing to address is the ceiling can lights if you have them. Unless they are zero clearance fixtures you cannot seal the holes on them. You must construct a small box or cover that allows air to move around them. These boxes can be built out of foam boards, wood, Sheetrock, or we use the round tubes used for cement. We place these around the lights and seal them into place with spray foam. Inside we then change the bulbs to compact florescent bulbs. Low heat and safer. Also saves money on power as well.

Inside the basement or crawl space. You also have much like the openings in the attic the same in the basement crawl space area. Pipes, wires, heating and cooling ducts, all allow air to flow up through the living area pulling heat and cool air out with it. Seal the openings the same way as the attic. Spray foam. Have larger holes? Plug them with insulation and then cover with foam. The whole idea is to stop the air flow upward through the home.

Inside house. Remove all fixture covers on outlets and switches. Purchase from any big box store gaskets to seal these boxes. Simply place gasket on back of cover and re-attach. This prevent air from being pulled into or out of the walls. All energy robbing areas.

AC system. You need to seal the ducts. Every seam you can see leaks air. With some older systems leaking as much as 30% of their air out of or into the system. When leaks occur outside of the heating and cooling envelope area such as a damp basement or crawl or even an attic the conditioning system must treat this air and remove moisture in summer as well as heat, or heat the cold air that enters during the winter months.

A simple fact is that you can take a 90% efficient furnace and attach it to a duct system that has not been properly sealed and the end result is only a 75% efficient furnace delivery over all.

Your windows which can be the easiest thing to correct is not about putting in double pane glass but to seal gaps that allow for air loss. Of course you will gain benefits out of putting higher U value windows in, but when your on a budget as most of us are sealing with caulk and window plastic or simple storm windows can help a lot. Simply putting in new windows is probably the worse initial investment you would make. If your doing it just to save money. Paybacks on high end windows can be as much as 50+ years before you see your savings. So putting plastic on is a good idea.

There are several window sealing kits from 3M that work well. These can be purchased at most big box stores and require little effort to install.

Regardless of what path you choose, if you stop the air flow you will save money.

Bob

Wall insulation-There are companies that are very good at installing it in walls from outside or inside. Usually they try to go from outside. I think you would be surprised how well they can do the job without you having to replace your siding! (See Windows below). First; do you already have insulation in your walls? Maybe, carefully remove a electric outlet/switch cover and investigate.

Windows-Vinyl replacement windows do not normally need any modifications to the siding. The siding is not touched.

I think if you shop around (keeping Apples for Apples in mind) you could get some quality windows that would pay for themselves within a few years.

All these entities- if done poorley are just a waste or worst of money. Its too bad you couldn't find someone there locally that knows what they are doing to somewhat oversee things.

Feel free to call me anytime for advise.