Prior to a revision of Building Regulations in 2010, ventilation was not high on the list of priorities in the housebuilding sector. A fan in the bathroom and cooker hood in the kitchen, plus ventilation blocks in the walls, were the default setting. Then, gradually, ventilation began to make it on to the agenda, largely driven by the now-defunct Code for Sustainable Homes, writes Paul Williams, Domus Ventilation’s Product Manager.