The spaces in which people live and work have a profound effect (0) ON their psychological wellbeing, a fact that architects and urban designers are only now beginning to take seriously. Research has shown that natural light, access to green spaces, and the proportions of a room can all influence 1 people feel and perform. Hospitals designed with patient recovery in mind, for example, have been found to reduce healing times, while classrooms with adequate ventilation and natural light have been linked 2 improved academic performance. What is perhaps most surprising is the degree to 3 even subtle design choices — such as the colour of walls or the height of ceilings — can affect mood and behaviour. Despite 4, relatively few buildings are designed with the occupants' psychological needs as a primary consideration. Cost and functionality tend to take precedence, and it is not 5 problems emerge — high staff turnover, poor productivity, or low patient satisfaction — that attention turns to the built environment. Were architects to collaborate more closely with psychologists from the outset, many of these issues could 6 avoided altogether. Promising 7 some recent developments in this field are, a fundamental change in the way buildings are commissioned and designed has 8 to materialise on any significant scale.