Modern buildings can and do overheat.
The inclusion of lightweight construction methods, improved air tightness and at times inappropriate quotas of glazing can result in buildings which become extremely hot during the summer. This issue can significantly reduce the productivity for the building’s occupants and lead to costly remedial measures if not adequately accounted for.
This need not be the case.
Through the use of a thermal simulation and overheating analysis, internal thermal comfort levels can be assessed prior to the construction of the building. This information can be used to inform the architectural design, construction specification, ventilation strategy, HVAC specifications and so forth.
Through the appropriate application of an overheating analysis, thermal conditions can be designed to achieve appropriate levels of comfort, whilst project costs can be minimized. Though it has not historically been the case, the task of designing a comfortable internal environment which is energy efficient should lie beyond the responsibility of M&E engineers alone. Building shape, orientation, layout and glazing quotas all play a significant role in the thermal behaviour of a building.
The most appropriate time for an initial thermal assessment is during the early concept stage. Where the appointment to carry out an overheating analysis is left late, the potential to achieve high performance gains are often lost. Certain buildings types, such as medical centres and buildings with large quotas of cellular spaces, can often have a high potential for overheating. To avoid these risks, please see our guide to avoiding overheating or reference other suitable guides, such as CIBSE TM36 and TM37.
Note should be taken that Part L2A Criterion 3; ‘Limiting the effect of solar gains’ is not an overheating assessment. Where contracts call for an assessment of overheating risk, or where it is otherwise considered prudent to do so, a separate overheating analysis shall be necessary.
We carry out overheating analysis to the industry standard definitions listed with this section, but can assess simulations based on custom criteria where necessary. It is always important to consider ‘what is the definition of overheating?’ on a project specific basis. For more information, please refer to the other pages in this section.