The most important step a homeowner can take toward making effective, affordable upgrades is to plan ahead. There's no point in spending money only on added insulation, for example, if your house's windows leak so much air that they render the insulation ineffective. Simple fixes, like sealing air leaks and installing insulation, can be extremely cost effective if they're done properly.
The best way to determine where you can earn the most eco-friendly bang for your buck is by conducting a home energy audit [source: Energy Savers]. Your budget may dictate whether you hire a professional to conduct this thorough inspection or you perform it yourself with guidance from resources like the U.S. Department of Energy. Either way, the audit will allow you to list your home's weakest points, which contribute to the majority of your home's lost energy. Fixing these problems first will generate the most savings in the shortest amount of time.