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Supplier Feature
How cladding can play a key role in passive cooling
For decades, buildings in the UK have been designed to keep people warm. Increasingly, the challenge is keeping them cool. Lisa Grosse, product and marketing lead for Cedral UK and Ireland, looks at how the intelligent use of ventilated cladding can help to reduce solar gain in buildings.
ON older buildings, brickwork absorbs large quantities of solar energy throughout the day, before slowly releasing that stored heat overnight. Newer developments, such as high-rise apartments and student accommodation, face challenges associated with glazing and airtight construction.
The question is no longer simply how we insulate buildings, but how do we create building envelopes that perform intelligently throughout the entire year? Fibre cement facades can help here.
Climate control Unlike traditional external finishes, rainscreen facades create a ventilated cavity between the external cladding and the insulated wall construction. As solar radiation heats the outer skin, warm air naturally rises through this cavity and escapes before significant heat can transfer into the building.
Research from BRE has highlighted the role of ventilated facade systems in improving summertime thermal performance, particularly as overheating becomes more common in UK buildings.
Envelope thinking Material selection is becoming increasingly important as temperatures continue to rise. Fibre cement offers a particularly robust alternative to timber and dark
masonry surfaces. Dimensionally stable, resistant to moisture, rot and insect attack, and requiring minimal maintenance, fibre cement has been developed to withstand repeated thermal cycling without compromising performance. This durability makes it especially suited to the increasingly volatile weather patterns experienced across the UK.
Gimme shelter One of the most effective passive cooling strategies remains external shading. Working with architects, contractors have long used projecting roofs, deep reveals and brise soleil to reduce solar gain. Increasingly, facade systems themselves are becoming part of that solution.
Brise soleil panels, such as those manufactured by Cedral’ s partner brand Equitone, are seeing renewed interest as designers seek passive ways to manage solar gain. Installed as horizontal or vertical screening elements, they intercept direct sunlight before it reaches glazed facades, helping to reduce internal temperatures while preserving daylight and outward views.
Passive measures first While air conditioning systems are not banned for new builds in the UK, the government has adopted a‘ passive measures first’ policy when it comes to housing design. Outlined in Approved Document O, the rules clearly state that mechanical cooling can only be used where enough heat can’ t be removed without it.
Contractors and architects need to demonstrate first serious consideration of things like window design, shading, ventilation and reducing solar gain – before aircon can be specified.
New and retrofit facades New-builds and refurb projects provide great opportunities for facades to reduce heat in buildings. Insulated rainscreen systems enable improved thermal performance while simultaneously transforming appearance, protecting ageing structures and enhancing occupant comfort.
Rather than treating overheating as an unavoidable consequence of climate change, retrofit facades allow contractors to intervene at the building envelope itself.
Best of both worlds Projects such as the Somerset Energy Innovation Centre demonstrate how contemporary fibre cement facades can combine good design with long-term durability through a ventilated facade system designed for modern environmental performance. Likewise, a new housing development commissioned by Galway City Council illustrates how fibre cement cladding can create an attractive exterior, while delivering improved weather protection and insulation as part of a wider housing design strategy.
As temperatures continue to rise, builders are being asked to create homes that consume less energy while remaining comfortable throughout increasingly extreme weather. To support this, merchants need to have access to high quality, fully tested facade systems – something Cedral is working hard to deliver. Cladding is no longer simply the face of the building. It has become one of its most important environmental systems.
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