What is CIBSE TM59?

CIBSE TM59 has been published to specifically address overheating risks in dwellings, as opposed to TM52 which was developed to address thermal comfort in workplaces. The same underlying calculation methods of TM52 are used, but the criteria are superseded with standards more relevant to residential occupation.

The aim is to produce a test that encourages good design that is comfortable within sensible limits, without being so stringent that it over-promotes the use of mechanical cooling.

What type of buildings are covered by TM59?

TM59 is relevant for all dwelling type properties – houses, apartments and also residential institutions such student accommodation, nursing homes, or other institutions of care due to illness or other physical or mental condition.

This methodology is proposed for all residences and should especially be considered for:

• large developments
• developments in urban areas, particularly in southern England
• blocks of flats
• dwellings with high levels of insulation and airtightness
• single aspect flats

TM59 has detailed compliance criteria, which differs dependant on ventilation type, and room type. There is a set of defined profiles which cover occupancy, lighting, and equipment heat gains.

Dynamic simulation modelling is the only way to demonstrate compliance with TM59.

Next Steps

By undertaking these calculations the risk of overheating in your project can be identified at an early stage and a solution provided.

Walker Energy Analysis are qualified and experienced professional who can carry out TM59 calculations for all dwelling type properties and a detailed knowledge of the legislation.