Groundbreaking new research commissioned by Steel Construction Institute (SCI) strongly rebuffs construction industry concerns that lightweight timber frame construction performs poorly with respect to the risk of overheating when compared with traditional forms of construction.
In fact the research, undertaken by Oxford Brookes University, demonstrates that the risk of overheating in a house built with lightweight framing is comparable to that of a house built to current standards with brick and lightweight block.
The subject has come under the microscope as high levels of thermal insulation and airtight fabric in modern residential building have raised concerns that recently built dwellings – of all forms of construction - will have a tendency to overheat during periods of hot weather.
Not only that, but there is further concern that global warming may push up temperatures in the UK over the next 50 years, within the lifetime of the dwellings built today, and that this could exacerbate potential overheating.
To investigate the risk of overheating for different construction types under different climate assumptions, a dynamic thermal simulation model of a typical three-bedroom house was developed using, a dynamic thermal model from Environmental Design Solutions Limited that allows modeling of the internal temperatures of a building as well as its heating and cooling demands.
Four construction systems were considered in this analysis: lightweight, mediumweight, heavyweight and very heavyweight. The first is considered to represent modern, lightweight, framed construction, the next two represent typical forms of brick and block construction and the fourth is included for completeness but is considered to be unrealistically heavyweight.
The results of this study showed that thermal mass in domestic buildings has a negligible effect on overheating during occupied hours. However it also highlighted that if the climate warms in the future, the risk of overheating may well increase. For this reason, the study maintains it is sensible to consider cooling strategies that will mitigate this risk and hopefully avoid the need for air conditioning.
As climate change progresses over the next few decades it will remain critical that the dwellings produced have both a low carbon impact and remain comfortable in what is likely to become an increasingly severe climate,” said Rupert Scott, TRADA Membership & Marketing Manager. “The findings of this study are therefore reassuring in that lightweight frame construction has the capacity to meet both these needs in a cost-effective manner.”