By Jim LaRue

The greatest heat loss is usually from air leakage, and the older the home the more leaky!

Taking that into consideration, the most cost effective place to stop air leakage is in the attic, and despite what you might have been told, the least cost effective is window replacement. The logic is if you stop warm air going out there will be a lot less cold air coming in through the windows.

So if we rate weatherization methods from most important to least, the first place to begin is the attic—sealing it for leaks and insulating. Once that is done, blowing insulation into sidewalls is the second best place to insulate.

If you have a basement crawlspace, it counts as the third best insulation site (this should be done around the perimeter walls of the crawlspace, not between the floor joists).

Insulating the perimeter joists at the top of the foundation walls of your house is next, followed by insulating the foundation walls. However, it is important to note that no wall surface materials should be damaged because moisture intrusions might occur in the future.

Of course, when you tighten your house, through insulation or other means, you need to be careful to effectively ventilate moisture from baths and kitchens. The good news is that you might find that humidifiers on furnaces are no longer necessary, however in some cases with new construction a new ventilation system might be required in order to bring in fresh air as polluted interior air is exhausted.  

Another important thing to remember is that if your house has the old knob and tube wiring you should upgrade or replace the system before you insulate. There may be a higher risk of fire from the insulation next to the wires, and you don’t want to spoil all that work by tearing it out to replace wiring in the future.

After sealing and insulating, you will be better able to determine how much capacity your heating/air conditioning system needs to provide. If all works well, you might even need a smaller heating/cooling system.

The best way to evaluate what your house needs, in terms of weatherization, is to have an energy audit done by a building performance professional, or start here to get an idea of what you can do.

Homeowners can get a list of professionals from the Ohio Department of Development’s Office of Energy Efficiency. Look for HERS Energy Raters, and a list will be provided. An energy audit can cost from $250 to $400 depending on the size of your home. They will provide you with a plan of action for weatherizing your home. For information about energy loans, funding and weatherization programs go to the Ohio Department of Development  or to Energy Star.

For the best, affordable book on the subject of weatherization, get a copy of Bruce Harley’s Insulate and Weatherize (Taunton Press, $20). It will help do-it-yourselfers save a lot of time and money and educate homeowners contracting the work so they better understand what is required and appropriate. The book is in a magazine format with loads of pictures and illustrations that you will find helpful.