Open windows and doors, use fans, and set your aircon to pull fresh air from outside.
Air purifiers with a HEPA filter are an expensive option. Plugging ventilation holes in walls helps, but there are also dangers.
From Opal Tower to Sculpture by the Sea, we look back on the top UNSW Built Environment stories in 2019.
Australian classrooms are recording high levels of carbon dioxide and other pollutants, says Built Environment Professor Mat Santamouris.