16 Aug 2018
It’s hard to ignore the recent press that this topic has been generating in response to one of the hottest summers that Europe has experienced in decades. Buildoffsite have hit back at challenges to the performance of lightweight modular homes. Bob Ward, policy and communications director at the LSE's ESRC Centre for Climate Change Economics and Policy and deputy chair of London Climate Change Partnership (LCCP), in a recent article published in the Guardian, has expressed equal passion about his serious concerns about the risk of overheating.
The Concrete Centre understands the unease of Bob Ward, who wrote “As ever, those who are least able to deal with the problems are quite often the ones most deeply affected by them, and when developers cut corners on design, occupants usually pay the price”.
Building Physicist and thermal performance expert at The Concrete Centre Tom De Saulles’ is of the view that the Environmental Audit Committee were right to instigate the Heatwave Inquiry and subsequently express concern about overheating and modular homes in their recent report entitled ‘Heatwaves: adapting to climate change’. Tom said “the Committee is right to express unease about the overheating issue in respect of modular homes, this can be more of an issue in lightweight homes that have little inherent thermal mass.
The guidance we provide to designers about how to use thermal mass, when used in combination with shading and ventilation for cooling in summer is essential in managing the risks of overheating. Although these passive measures may need to be supplemented with active cooling in some climate change models and in some building types, such as high-rise apartments, these important performance criteria should not be compromised as we try to meet the undoubted and urgent need for more housing”.
The Concrete Centre provides technical guidance on reducing overheating and in the past has worked with the Zero Carbon Hub and is now working with the Good Homes Alliance to provide evidence-based best practice to planning departments on the risks of overheating. Tom continues “It is so important that proven performance and evidence shapes this debate, to provide housing that is resilient to climate change and will perform now and in the future”.
The Environmental Audit Committee report, which says “modular homes are not resilient to heatwaves”, recognises that many factory-produced homes are of lightweight construction and lack thermal mass.
Andrew Minson, Executive Director of The Concrete Centre added “Unsurprisingly those in the offsite sector who produce lightweight systems are not happy about the Committee’s stand on this point, but the fact remains that thermal mass offers an effective means of helping reduce overheating when used in conjunction with good ventilation and solar shading.
If we are going to tackle the problem of heatwaves without resorting to energy intensive air conditioning then we are going to need to employ all the passive measures available to us, of which thermal mass, inherent in masonry and concrete, has an important role to play.”
Read more: Overheating: An extract from Resilient Homes
Read more: Thermal Mass Explained