Building Compliance
During the design of your project, it is important to ensure that not only the dwelling is insulated well but also does not overheat across the year. Overheating assessment may be required to design around non-compliance overheating issues, as part of planning permission or as part of an energy statement.
Overheating risk has become a critical consideration in UK building design. As summer temperatures rise and building fabric performance improves, managing internal comfort is no longer secondary to energy efficiency. Vision Energy provides professional overheating analysis services across the UK, supporting residential, commercial and educational developments.
## Part O, TM59, TM52 and BB101 Explained
Part O focuses on residential overheating risk and is now mandatory under the Building Regulations. Compliance is commonly demonstrated through TM59 modelling, which evaluates factors such as the number of hours above adaptive comfort thresholds and night time temperature control within bedrooms.
TM52 applies to non residential buildings and uses adaptive comfort theory to assess the extent and duration of temperature exceedance. It is often used for offices, mixed use developments and commercial spaces where occupant comfort must be demonstrated.
BB101 is specific to educational buildings and incorporates criteria tailored to classroom occupancy patterns, internal heat gains and ventilation strategies. Overheating analysis for schools requires particular care in modelling realistic use scenarios and ventilation performance.
Understanding the distinction between these standards ensures that assessments are correctly scoped and aligned with project requirements.
Our overheating assessments begin with a detailed review of architectural drawings, glazing ratios, façade design and ventilation strategies. Key inputs such as occupancy profiles, equipment loads and local weather data are incorporated into a dynamic thermal model.
Simulations are carried out to evaluate temperature performance across representative spaces and orientations. Where risk is identified, we provide clear and proportionate recommendations that may include adjustments to shading, glazing specification, ventilation design or façade configuration.
Reports are structured for submission to Building Control or planning authorities and clearly demonstrate compliance with Part O, TM59, TM52 or BB101 as required.
Overheating compliance should not be approached as a late stage check. Introducing dynamic thermal modelling during concept or developed design stages allows teams to understand how orientation, glazing strategy and ventilation approach influence internal comfort.
Early assessment reduces the risk of redesign, supports planning submissions and strengthens the overall sustainability narrative of a project. It also ensures that measures introduced to improve airtightness and energy efficiency do not inadvertently increase summer overheating risk.
As buildings become more efficient and climate conditions continue to evolve, overheating analysis is increasingly central to responsible design.