Dr. Iain Walker is a scientist at Lawrence Berkeley National Laboratory (LBNL). He has more than 20 years of experience as a building scientist and consultant, conducting research on energy use, ventilation, moisture, performance simulation, and commissioning/diagnostic issues in residential buildings. His current work focuses on retrofits, Zero/Low Energy Homes and heating, ventilation, and air-conditioning (HVAC) systems in residential buildings through field and laboratory evaluations, modeling and simulation activities, and standards setting. He is Executive Editor and member of the board of Home Energy magazine. He is the task group leader for the American Society of Testing and Materials (ASTM) standards committees on building and duct system air leakage and sealant longevity. For the American Society of Heating, Refrigerating, and Air-conditioning Engineers (ASHRAE) he serves on National Standards committees for indoor air quality, weather, moisture design, and equipment air leakage. He also serves on Building Performance Institute (BPI) and Residential Energy Services Network (RESNET) Technical Committees, the Affordable Comfort (ACI) conference planning committee and provides leadership and technical input to many local, state, national and international bodies.