HSE have produced a number of publications for employers to help ensure their premises are as safe as possible during the current climate.
The government guidance reminds employers of their legal responsibilities for the safety of those entering workplaces:
"To help you decide which actions to take, you need to carry out an appropriate COVID-19 risk assessment, just as you would for other health and safety related hazards. This risk assessment must be done in consultation with unions or workers."
Undertaking this risk assessment may require advice from competent persons, such as professionally registered engineers who are Chartered or Incorporated Engineers and registered with the Engineering Council.
CIBSE have published COVID-19 Ventilation Guidance and Fraser Walker Associates are able to assist clients in risk assessing their ventilation systems.