Overheating Analysis TM59 / Part O / TM52
When designing a project, it is important to ensure overheating is not an issue across the whole year, this is to provide a good level of thermal comfort as well as limit the need for additional cooling where required. High temperatures in buildings on the very bottom line is not a comfortable environment to live or work. Therefore completing an Overheating analysis can avoid this.
CIBSE has produced guidance in the form of TM52, TM59 and Guide A, these guidelines set out the criteria to ensure that overheating within a building is not present. The different guidance covers commercial and residential and if the building is cooled, naturally ventilated and mechanically ventilated to be certain the correct criteria is set for the building type and design.
In the transition between 2021 & 2022, Building Regulations Part O was published to assess overheating risk in summer months for residential new build dwellings, Part O overheating analysis has two options for compliance as listed below
- Simplified route – an assessment undertaken based on window sizes, orientations and percentages compared to sizes
- Dynamic Simulation method – This method includes thermal modelling of the proposed development and analysis the overheating risk across an hourly/daily basis.
Part O Overheating Assessments are best carried out at an early design stage to ensure that the development meets compliance to Part O.
In designing your project to eliminate overheating risk, we would use thermal modelling techniques that take into consideration schedules, equipment, people and solar gains as well as the thermal performance of the project to be able to design a natural or mechanical ventilation strategy to reduce the risk of overheating. This may be just part of your design process or this could be as part of a planning condition, Energy statement or based on a failure for overheating within Part L calculations.