As we increase the air tightness of our buildings in line with more stringent building regulations it is vital to specify adequate fresh air ingress to all occupied spaces to ensure the health and well-being of occupants. In order to optimise buildings for energy and health it is important that we have a comprehensive understanding of the dynamics of indoor air flow, which is complicated by the impact of human behaviour. Current knowledge of how humans interact with their environment and implications for the airflow within buildings is virtually non-existent. This proposal aims to develop facilities for investigating the detailed fluctuations of air movement due to occupants opening and moving through doorways. This will have a significant impact on the understanding of contaminant transport and fresh air ingress into buildings; it will also have implications for ventilation specification and simulation as well as building energy prediction.