What is Weatherization
"Weatherization as defined by the Weatherization Assistance Program (WAP) differs in many ways from what is commonly called "weatherizing your home." The latter involves low-cost improvements like adding weatherstripping to doors and windows to save energy. These measures made up the services WAP provided in its early years and are likely responsible for the program's name."
Read the full description of weatherization from the Office of Energy Efficiency & Renewable Energy.