I'm a ventilation expert working as a research associate at the University of Nottingham assessing the role of the built environment on the risk of Covid transmission. I am also the chair of the CIBSE Natural Ventilation group and have co-authored the CIBSE Covid Ventilation Guidance and the CIBSE Air Cleaning Technologies guidance. I have a background in biochemistry and have worked in the built environment for the last 15 years.