As Europe Gets Hotter, Insulation Keeps You Cool

To quote a popular song from the early 2000s, ‘it’s getting hot in here’. But, unlike the people in the song, most of us don’t have the option of taking off all our clothes. Instead, we need to find other ways to stay cool on a hot summer day. 

Domen Ivanšek is Head of Building Science at Knauf Insulation.

A good place to start is with our buildings and homes.

Buildings have the potential to be our first line of defence in the fight against climate change. Not only can an efficient building help Europe achieve the twin goals of energy sovereignty and climate neutrality, it can also help protect people from overheating.

Heat related illnesses are a growing concern in today’s increasingly hot world. Children, older people and those with medical conditions are especially vulnerable to overheating. When you take into consideration Europe’s ageing population, more people will be at risk in the future. In fact, according to some estimates, extreme heat will impact 300 million Europeans annually by 2100 and kill 90,000 people a year.

But make no mistake, the risk of overheating is by no means limited to being outside – it’s an inside hazard too. Europeans spend as much as 90% of their time indoors. If these spaces aren’t thermally comfortable, occupants could suffer. 

The problem is that the building and construction sector has been largely focused on keeping people warm – and rightly so as Europe currently experiences more than 200,000 deaths every winter. However, with climate change and the record-breaking temperatures and extreme heatwaves that come with it, it’s now just as important to keep people cool in summer too. 

A Holistic Approach for Year-Round Resilience 

The good news is that buildings can help protect people from both winter and summer extremes. The key to providing such year-round climate resilience is to take a holistic approach to building design. 

A holistic approach incorporates a range of factors. For example, it might include optimising glazing and shading or incorporating vegetation through living roofs and walls so solar heat gain is balanced throughout the seasons. One could also consider a home’s orientation in relation to wind and peak sunlight.

Ventilation and airtightness are additional factors to consider. Carefully managed ventilation within an appropriately airtight building will allow for greater control over the internal temperature. 

Beyond the building’s design, a holistic approach will look to manage internal heat sources as well. By insulating elements like hot water pipes and installing energy efficient appliances, we can help make sure neither contributes unwanted heat within the building. 

Insulation – It’s Not Just for Winter

One essential component to ensuring a building’s year-round comfort and protection is to maximise the use of quality thermal insulation.  

That’s right, insulation isn’t just for winter. 

Because its main benefit is felt during the winter, people tend to think of insulation as a blanket. But really, it’s better to think of insulation as a thermos: when it’s cold outside it keeps the inside warm, but when it’s hot outside it does the opposite and keeps the inside cool.  

Insulation creates a year-round stable indoor environment by preventing unwanted heat transfer. In the winter, this means slowing heat loss from interior spaces. In the summer, it means reducing the amount of warm air coming in. In addition to keeping heat from coming in through the exterior walls, insulation can also help prevent the hot, humid air of an attic from seeping through the ceiling and into the home’s living space. 

Optimising HVAC Use 

While passive cooling solutions (opening windows, insulating pipes, using energy efficient appliances, etc.) can significantly reduce the risk of overheating in much of northern and central Europe, in the Mediterranean Region it’s a different story entirely. Here, summer temperatures have been brutal – with places like Sicily seeing scorching daytime temperatures of 48°C and higher. And there’s no respite at night, with tropical nighttime temperatures of 20°C or more now being the norm. 

In the face of such round-the-clock heat, even the most holistically designed building will need some mechanical help. Luckily, when properly installed as part of a holistic building design, quality insulation creates the stable internal environment needed to optimise the use of heating, air-conditioning and ventilation (HVAC) systems like heat pumps.   

Contrary to what their name suggests, heat pumps can also be used to cool a home. When that home is properly insulated, the heat pump doesn’t have to work as hard to maintain a comfortably cool climate. This in turn reduces both energy use and costs.   

Let’s Make Insulation Do More

As Europe’s climate continues to change on both ends of the seasonal spectrum, it is now critical that we take the necessary steps to fully leverage the year-round benefits of a climate resilient building. To do so, we must ensure that the buildings being built or renovated today are future-proofed against the climate of tomorrow. 

As a first step, policymakers must work to ramp up building renovation rates, with a particular focus on improving such critical passive building envelope elements as thermal insulation, along with airtightness, windows and shades. This will keep buildings not only warm during the winter, but also cool in the summer. It will also ensure that, if an active cooling system like a heat pump is installed, its design and use will be fully optimised. 

When used in combination with holistic building designs, insulation can do more than just keep us warm in the winter and cool in the summer. By reducing not only overall, but very importantly, peak heating and cooling demand, it opens the door to the use of clean, efficient HVAC technologies powered by renewable energy sources. 

It can also serve as the foundation of a more robust, climate-resilient and safer built environment – one capable of protecting us from the impacts of climate change 365 days a year.