Adduces the economic advantages of weatherstripping for energy conservation, performance criteria and future developments in materials and fixings. Mentions the advantageous psychological response of personnel. Describes the factors influencing performance - window section, location of seal andinstallation method. Briefly describes the work of the Draughtproofing Advisory Association (DAA). Refers to BS 4315 and demonstrates need for new standards based on air flow measurement round total opening perimeter. Describes briefly the air infiltation testing carried out by Schlegel (UK) Engineering Ltd.