TM52 and TM59 were developed to address the issue of overheating in buildings (TM52) and in residential homes (TM59) in the face of a changing climate. While the methodologies are similar, TM59 has been developed specifically to address the risk of overheating in homes compared to other buildings.

TM59 as assessed using simulations based upon a 24 hour occupancy assumption to take into account thermal comfort at all times of day. CIBSE has outlined required temperature limits that must not be exceeded more than a set out percentage of hours, including night time temperatures so that sleep patterns are not disrupted.

The first part of this criteria surrounding percentage of occupied hours that should not exceed threshold temperatures is shared with the criteria of TM52.

GreenBuild is able to run simulations to execute these methodologies and provide recommendations on building projects in line with TM52 and TM59 criteria. If these are followed this results in a more energy efficient building through the utilisation of natural ventilation and reduce the risk of overheating in the face of a changing climate.