How holistic design and simple solutions can make our buildings more heat resilient
October 17, 2023
We urgently need to address rising temperatures in our communities. So, let's explore a holistic approach to heat resilience.
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Summer 2023 featured the globe’s two hottest months on record, back-to-back. Even in the Autumn, London recorded its hottest temperature for October in the last five years. Undoubtedly, these are very stark signs the climate crisis has arrived, with huge numbers of people already experiencing extreme heat and volatile weather.
The UK is not the worst affected, and never will be. But the steady rise in average temperatures and increased regularity of heat spikes is focussing the minds of policy makers. Several factors mean that our existing buildings aren’t very heat resilient. Arguably the most important element is age. The UK has the oldest housing stock in Europe, with almost 40% of homes built before 1946. Older buildings tend to be poorly insulated and built to capture sun, rather than shade from it. In this context, the Environmental Audit Committee’s (EAC) inquiry into heat resilience and sustainable cooling in the UK’s built environment is most welcome.
Finding less energy intensive ways to keep buildings comfortable is vital to meet our net zero goals. We simply must break the cycle of requiring more energy to protect against ever warmer temperatures. Much of this comes down to common sense. As planners, designers, and engineers, we must get the basics right. This means thinking holistically about natural solutions and acknowledging the context we’re designing within. For us, this also means having a focus on breaking down barriers between disciplines and bringing expertise and knowledge together.
In September 2023, the UK had an unprecedented seventh consecutive day of 30C heat.
Simple solutions and natural remedies
Passive design solutions are a central part of sustainable cooling. They include simple options that need to be more common. Improving insulation to reduce heat exchange, cross-ventilation, or rethinking the orientation of our homes, for example. Fundamentally, reducing overheating in summer, while still offering light in winter is the key. Simple moves such as dual-aspect properties that do not face directly south can help hugely.
Buildings in warmer climates have long embraced exterior shading and covered colonnades, such as our work on the Southern Dunes Hotel in Saudi Arabia. In the face of a challenging context, this building was specifically designed to maximise comfort and luxury, while minimising its environmental impact and achieving a LEED Platinum rating. An extreme environment, but there are still lessons in this for the UK. Getting the basic design of a property right is the biggest positive factor in ensuring heat resilience. Then any required technological solutions or assistance can be layered on top.
Getting the basic design of a property right is the biggest positive factor in ensuring heat resilience.
Designs that are sustainable and fit for the future must also go beyond the built structure. Nature-based Solutions that work in harmony with the natural environment, and even enhance it, are critical to success too. Temperatures across whole areas can be lowered through the creative use of landscaping, tree planting, water, organic shading, and natural materials. In turn, this supports the resilience of our buildings and open spaces.
Embracing nature in design is climate-friendly and creates more livable places. To achieve this, architects, landscape designers, technical specialists, masterplanners, and more must work together. We need to value the cross-sector mindset that creates the sustainable, resilient spaces vital to survive today’s climate.
Challenges of context
Of course, these solutions are easier to apply to new builds, be it urban, suburban, or rural. But retrofitting and other adaptations are suitable for existing structures and high-density urban environments. Office units and apartments are particularly challenging. They are often single aspect and stacked to be cost and space efficient. This limits natural cooling. This is a socioeconomic problem too. Overheating of high-density blocks is much more likely and poses a real socioeconomic and environmental challenges.
In these cases, external shading and rethinking airflow offer the simplest improvements. At the Chocolate Factory in London, our architects are currently working on the refurbishment and design of a new office building within a wider regeneration scheme. To comply with overheating parameters in the Chartered Institution of Building Services Engineers (CIBSE) regulations, a series of enhancements have been made to the building, most notably to the fabric, space heating, and cooling strategy.
Our work on The Chocolate Factory in London has been designed with heat resilience in mind.
A new wall liner system will add a layer of insulation to the inside of existing external walls, increasing their thermal performance. All glazing has been replaced with high performance window units with solar control glass coating. This provides enhanced thermal performance over the existing windows for benefits in both summer and winter. Inside, mechanical heating and cooling is still needed, but made to be highly efficient and specific to individual office spaces. More often used in new office buildings, these techniques can and should be possible within retrofitted schemes.
Like many aspects of the climate crisis, the benefits of sustainable solutions go beyond net zero. Improving the temperature reliance of our built environment helps us to tackle inequality in living standards, while also improving livability for all.
We are therefore pleased to see the EAC’s inquiry launch. This will put a focus on sustainable resilience solutions to these challenges and encourage opinion from a wide range of disciplines and areas.
By bringing together both creative and technical expertise, and by starting with the basics, we can embrace simple solutions and appreciate the benefits of natural design to address this urgent challenge.