Brennan Lesshas spent nine years as a building science researcher at Lawrence Berkeley National Laboratory in the Residential Building Systems group and the Indoor Environment group. His current work focuses on state-of-the-art field measurements and simulations of smart ventilation systems, hygrothermal performance of sealed and insulated attics, indoor air quality, deep energy retrofits, zero net energy homes, and the health-energy efficiency nexus. He regularly presents his work at national conferences for the home performance and IAQ industries, and he is the author of over 20 research reports and technical journal articles. Brennan holds a Master of Science in Architecture degree from UC Berkeley – California (2012). He also has extensive experience as a home energy auditor and in residential construction and brings this hands-on approach to his research activities.