A fundamental shift in sustainable design thinking and practice has occurred over the last few decades. In particular, the increasing application of heat recovery ventilation (MVHR) is changing the way we envisage the home environment. Instead of passive, adaptive spaces, there is an increasing trend towards the creation of airtight envelopes, where dependence is placed on technological devices to condition the interior environment. This dependence however presents a number of challenges and risks that are of particular concern in a social housing context. This paper discusses the inherent challenges of technologically dependent ventilation in airtight housing in a temperate climate in Scotland. A door-to-door survey was conducted in 36 homes which investigated occupant behaviour and perceptions of ventilation in their home. The study identified issues with occupant use and control of ventilation, with particular concerns relating to the perception of MVHR systems.