Editor of Modern Building Services Karen Fletcher, looks at the challenges of overheating in our buildings.

As temperatures soared this summer, it became clear that 2018 was not a one-off year.

Figures show undeniably that average summer temperatures in the UK are heading upwards and while that may sound pleasant, we’re getting to the point where heat becomes dangerous.

While it is currently difficult to identify an exact number of deaths caused by the 2018 heatwave (figures should become available next year), the Environmental Audit Committee warned of 7,000 heat-related deaths every year by 2050 if more is not done to protect people from the worst effects of the heat.  

Extreme heat is just as deadly for the very young, elderly and infirm as the cold.

Encouraging end-users to re-think set points should also be on the agenda

Karen Fletcher Karen Fletcher Editor of Modern Building Services

None of this should be news to built environment professionals.

Numerous reports have been produced on the potential effects of warmer summers on our cities in particular. As far back as 2005, the Greater London Authority (GLA) produced a report titled ‘Adapting to climate change: a checklist for development.  

In the same year, Arup and the DTI (as it was then known) produced ‘Beating the heat: keeping UK buildings cool in a warm climate'.

The latest draft London Plan (due to go through its final comments stage in September 2018) has been criticised for not addressing the problem of overheating in homes and non-dwellings firmly enough.

However, the Plan has always contained calls to reduce the likelihood of overheating in both types of building, and points developers to CIBSE’s TM52 (2013): The limits of thermal comfort: avoiding overheating in European buildings.

Again, this is a technical guide that has been around for some time, and it opens with the words: “Overheating has become a key problem for building design.”

Built for cold

CIBSE also highlights one of the most challenging aspects of overheating for the UK. The fact is, UK buildings were constructed more with cold temperatures in mind.

As CIBSE points out, this means we end up with lightweight, highly insulated buildings that ‘respond poorly in the summer’.

And older buildings don’t fare much better as they are likely to be difficult to ventilate and offer little in the way of solar gain reduction.

For building services professionals, increasingly hot summers will mean that building owners and managers are turning to them more for help with internal heat reduction.

However, we can’t just add more cooling technology into buildings. That simply compounds our climate problems by requiring more energy use and adding CO2 to the atmosphere as a result.

Energy efficiency challenge

The challenge is not simply reducing heat, but doing so in a highly energy efficient way. This means ensuring that clients are using the most up-to-date technologies that comply with energy efficiency legislation.

There are also important options to consider such as heat recovery, which can take 'recovered' heat from occupied spaces and apply it to water for domestic services, for example.

And offering smart kit – that has built-in controls that help users cut energy waste, while optimising system performance.

Encouraging end-users to re-think set points should also be on the agenda. If outside temperatures are rising to 28°C, then an internal temperature of 21°C actually feels too cold to many occupants.

Letting indoor temperatures rise a little higher, while controlling humidity, keeps occupants comfortable and energy costs lower.

Transforming the very fabric

In July 2018, The Guardian newspaper commented on the long-term effects of increasing temperatures, saying: “It is underappreciated that climate change will transform the very fabric of the experience of living in the UK.”

As we move forward into a new type of UK weather, building services will be at the forefront of ensuring that we do so safely and responsibly.

Karen Fletcher is editor of Modern Building Services