After all the data gathering and testing we can perform the work needed to correct the problems. Air sealing and insulation are at the top of the list as the most cost effective solutions. After that it’s important to consider the heating and cooling systems. If you reduce the need for heat you can get a smaller more efficient heating unit and save money. Another simple and effective upgrade is to replace inefficient incandescent light bulbs with CFLs (Compact FLuorescents) or LEDs.