A 1977 STUDY ESTIMATED THAT APPROXIMATELY 25.5 MILLION HOUSING UNITS WERE IN NEED OF RETROFITTING AND THAT SINCE 1973-74 APPROXIMATELY 8 TO 9 MILLION HOUSES HAVE BEEN VOLUNTARILY RETROFITTED. RETROFITTING IS THE PROCESS WHEREBY MATERIALS AND PRODUCTS ARE PERMANENTLY ADDED TO EXISTING HOMES IN ORDER TO REDUCE HEATING AND COOLING ENERGY CONSUMPTION. EFFECTIVE RETROFITTING OF RESIDENCES COULD SAVE NEARLY 20 PERCENT OF THE ENERGY USED FOR RESIDENTIAL HEATING AND COOLING. HOWEVER, ADDING INSULATION, STORM DOORS, AND STORM WINDOWS IS COSTLY AND MAY BE BEYOND THE FINANCIAL CAPABILITY OF LOW-INCOME PERSONS. UNDER A FEDERAL PROGRAM, FINANCIAL ASSISTANCE FOR PURCHASING WEATHERIZATION MATERIALS IS PROVIDED LOW-INCOME PERSONS. THE MATERIALS AND PRODUCTS CONSIDERED ELIGIBLE FOR THIS PROGRAM ARE INSULATION, STORM WINDOWS AND DOORS, CAULKS AND SEALANTS, WEATHERSTRIPPING, VAPOR BARRIERS, CLOCK THERMOSTATS, REPLACEMENT WINDOWS, AND REPLACEMENT GLAZING WHEN USED FOR RETROFITTING RESIDENCES. ELIGIBILITY CRITERIA INCLUDE THERMAL PERFORMANCE, FIRE SAFETY, HEALTH SAFETY, STRUCTURAL INTEGRITY, DURABILITY, QUALITY, CONFORMANCE TO BUILDING CODES, AND USE AND EASE OF INSTALLATION. ELIGIBLE MATERIALS MUST COMPLY WITH APPLICABLE LOCAL BUILDING-RELATED CODES. THE RETROFIT MATERIALS ARE LISTED BY GENERIC TYPE, AND RECOMMENDATIONS ARE MADE FOR THEIR INSTALLATION. A LIST OF CONVERSION UNITS, TABLES, REFERENCES, AND APPENDIXES CITING NONELIGIBLE MATERIALS WITH ENERGY-SAVING POTENTIAL ARE PROVIDED. (AUTHOR ABSTRACT MODIFIED--PRG)