In a 2002 experiment on Alzheimer’s patients, researchers from Southern Illinois University found that changing the lighting in an interior reduced “sundown syndrome” symptoms – such as the wandering, repetitive statements and anxiety that tend to occur in the early evening – by 41 per cent during winter months and 11 per cent in the spring. The study is part of the growing body of evidence demonstrating that the design of living environments can make a big difference to those suffering from age-related illness and disability.

John Zeisel, a sociologist specialising in architecture, came to similar conclusions while working on a study for the US’s National Institute on Aging. He discovered that changing the physical environment in care centres had the effect of reducing Alzheimer’s symptoms.