The quality of the air that we breathe is incredibly important for a variety of aspects of our health. Whilst the air quality outside is subject to things such as pollution, we usually expect that our indoor air quality will automatically be cleaner and better for us, but this is not actually the case.

Over the course of history, most big cities have lost sizeable parts to fires. In 1666, the Great Fire of London destroyed a third of the city and left 100,000 people homeless. The Great Fire of Tooley Street in 1861 destroyed over 600 buildings. There have been countless other such calamities in cities around the world.