Overheating investigation in UK social housing flats built to the Passivhaus standard

Overheating assessment based on Passivhaus criteria, using a fixed benchmark, suggests there is a significant risk of summer overheating with more than two-thirds of flats exceeding the benchmark. While the level of overheating in different flats varies considerably, detailed analysis indicates that this is more related to occupant behaviour than construction. An alternative approach to evaluating overheating risk is the adaptive thermal comfort model, which takes into account occupant vulnerability and actual outdoor temperature. Use of the adaptive benchmark suggests this overheating risk is lower for normal occupants; but higher for vulnerable occupants. These results not only have implications for the evaluation of overheating risk but also for the way in which social housing landlords place tenants of differing vulnerabilities.