What effect do building and room occupancy levels have on transmission?
Managing the number of people in a building or room can have a significant effect on the risk of transmission.
Reducing the number of people has three effects – it reduces the chance than an infectious person is present, it reduces the number of people who can be infected, and, in some spaces, it can enable more distance between people, reducing the probability of proximity exposure.
Evidence suggests that reducing occupancy of buildings is one of the most effective strategies at preventing outbreaks of disease. (PROTECT COVID-19 National Core Study | Systematic review of risk factors for workplace outbreaks of COVID-19 – PROTECT COVID-19 National Core Study (manchester.ac.uk)) While this is not practical for many businesses, in times of high case numbers temporarily reducing occupancy through enabling some home-based working or cohorting teams can be very effective at reducing risk.