With the planet growing ever hotter, the world is becoming increasingly conscious of the environmental impact of having to artificially cool buildings. As such, architects and designers are incorporating passive solar shading solutions into their designs. This blog, the third published by Contrasol, explores the sustainability of these solar shading solutions, with a particular focus on brise soleil, a building feature specifically designed to minimise solar heat gain.
Brise Soleil works to provide effective shading of a building whilst also allowing natural light to penetrate a building’s interior. In its concrete incarnation, brise soleil was popularised by pioneer of modern architecture Charles-Édouard Jeanneret, otherwise known as Le Corbusier. However, it has taken countless forms over the years, including the huge, movable wings of the Milwaukee Art Museum, designed by Santiago Calatrava. In its modern form, these carefully designed and positioned brise soleil elements are designed not only to visually enhance a building’s façade, but work to reduce direct solar radiation and maintain optimal temperature levels, minimising the need for excessive air conditioning and significantly decreasing a building’s cooling load. The reduction in energy demand directly translates into lower energy consumption, resulting in reduced greenhouse gas emissions and a smaller carbon footprint.
1. Environmental Benefits of Brise Soleil
One of the key sustainability benefits of brise soleil is its ability to harness passive solar design principles. By strategically positioning brise soleil fins, architects and designers can optimise natural lighting while minimising glare and heat gain. The carefully designed and positioned brise soleil system works to block the intense direct sunlight during peak hours while allowing for indirect and diffused light to penetrate a building’s interior. The result is a balanced and comfortable indoor environment that reduces reliance on artificial lighting during the day, thereby reducing energy consumption. A simulation study of an office space, conducted in Qatar (a particularly hot country), showed that in south-orientated offices, energy savings of up to 36.3% could be achieved by the addition of brise soleil. Moreover, brise soleil and other similar solar shading solutions, allow for the controlled admission of daylight into a building, enhancing occupant productivity and well-being. Further studies have shown that exposure to natural light has positive effects on mental and physical health, leading to increased employee satisfaction and productivity in workplaces. By integrating brise soleil systems, building designers can create spaces that prioritise human comfort, sustainability and overall well-being.
2. Material Selection and Lifecycle Considerations
To maximise the sustainability of solar shading solutions, it is important to consider the choice of materials used. Opting for durable and low-maintenance materials with high recyclability or a long lifespan contributes to the overall sustainability of brise soleil systems. Additionally, the use of materials with high solar reflectance and low thermal emissivity further enhances their performance in reducing heat gain and energy consumption.
Brise soleil systems most typically use aluminium, timber or glass fins that create solar shading to a building’s façade, all of which have sustainability benefits. The use of aluminium as the most recyclable industrial material and can be recycled infinitely, typically recycling aluminium uses 95% less energy than producing aluminium from raw materials. It also saves 97% of greenhouse gas emissions produced in the primary production process. Timber louvres and fins offer an alternative to aluminium and should be sourced from sustainable forests that are in line with the Sustainable Forest Initiative. Well-managed forests support biodiversity, carbon sequestration and local economies. Timber is one of the most eco-friendly building materials, as wood naturally biodegrades at the end of it’s life cycle. Furthermore, trees remove large amounts of carbon dioxide from the atmosphere and has low thermal conductivity, meaning it will insulate buildings as well.
Glass is another sustainable material often used in brise soleil systems. Opting for eco-friendly glass options, such as low-emissivity (low-e) glass or insulated glass units (IGUs) can further enhance the sustainability of brise soleil systems, which provide improved thermal insulation and reduce heat loss. The highly recyclable nature of glass ensures that resources are conserved and helps to reduce landfill waste.
3. Working Practices
Working practices in brise soleil projects involve collaboration amongst architects, façade companies, structural engineers, contractors and specialised consultants. It is always important to consider the specific building regulations and requirements of any given project and adhere to industry best practices, such as providing Environmental Product Declarations (EPDs) for brise soleil products. The sustainability of buildings more generally and solar shading more specifically is covered in the Approved Documents of the Building Regulations, which are based on Eurocode standards adopted into UK law, such as ISO-14001. Managing this commitment at Contrasol, is our Health, Safety, Environment and Quality (HSEQ) department, which is led by Operations Director, Stephen Archer-Jones. Stephen manages a company-wide HSEQ strategy that goes beyond a moral and legal duty of care that ensures sustainability in all of Contrasol’s business activities.
4. Conclusion
Solar shading solutions such as brise soleil, offer numerous sustainability benefits, including reduced energy consumption, improved thermal comfort, enhanced natural lighting and aesthetic appeal. By integrating these shading systems into architectural designs, buildings can achieve a harmonious balance between environment responsibility and occupant well-being. As global warming necessitates the prioritisation of sustainable practices, solar shading solutions will undoubtedly play a vital role in creating sustainable and energy-efficient buildings for a greener future.
