What is brise soleil and why is it needed? The Long version
The craze for glaze
Favouring generous portions of glazing, modern architecture is fully embracing this trend to allow more natural daylight to permeate through to the interior of the building thus improving the wellbeing and general comfort of its occupants. Also offering a view of the surrounding external area as an alternative focus for those who use computers, for example, and must have regular breaks from their screens. Large glazed areas also create a sense of space and air in what could ordinarily be a dim and claustrophobic environment as well as being aesthetically interesting and attractive to the onlooker.
However, issues with temperature control can arise in buildings that feature large quantities of glazing where there is an increased risk of overheating and, possibly, unbearable conditions for the occupants, therefore, the requirement for air conditioning to be installed is vital. Depending on the extent of solar gain (increase in temperature of a room, object or structure as it absorbs short wave solar radiation) and subsequent consumption level of cooling energy this could mean a sizable electricity bill especially as energy prices increase, not to mention the potential issue of noise pollution from air conditioning units as well as their maintenance and this, of course, won’t mitigate the problem of glare from the sun.
The orientation of a building will also be a contributing factor to solar gain absorption – different elevations of a building will absorb varying levels of solar gain. A south facing office on the 6th floor, with a large glazed area, for example, will experience far more solar gain than an office that is either on a lower floor or north facing. With the increasing propensity to build up, rather than out and as available land can be at a premium with the need to preserve greenbelt land paramount, buildings are reaching further into the sky and therefore exposed to the elements with very little shade or shelter.
The technical stuff
During summer months the sun rises to an angle of 62° with an average of 6 hours of sunshine and on the longest day, there is the potential for the sun to be shining for about 16 hours. Whilst some embrace the sunshine it can be extremely detrimental in commercial premises, where employees are expected to perform at a high level all year round. These unnecessary distractions can affect staff morale and consequently productivity.
The Workplace (Health, Safety and Welfare) Regulations 1992 (SI 1992/3004) state that, during working hours, the temperature in all workplaces inside buildings should be reasonable. However, the Regulations do not provide a maximum workplace temperature. What is considered reasonable depends on the nature of the workplace and the activities are undertaken therein.
The Health and Safety Executive (HSE) previously defined an acceptable zone of thermal comfort for most people in the UK as sitting “roughly between 13°C (56°F) and 30°C (86°F), with acceptable temperatures for more strenuous work activities concentrated towards the bottom end of the range, and for more sedentary activities towards the higher end”. The HSE’s current stance is that it isn’t possible to give a “meaningful” maximum temperature, as other factors such as radiant temperature, humidity and air velocity become more relevant in workplaces with high temperatures, such as glass works or foundries.
Brise soleil is for life not just for summer
During colder months and shorter daylight hours, the heat and light from the sun can be very welcome and immensely beneficial, particularly for those who suffer from Seasonal Affective Disorder (SAD), however, the lower position of the sun and its increased intensity during these months means that buildings can still overheat and people will continue to be highly susceptible to its dazzling glare leading to visual strain and uncomfortable conditions.
It’s also worth considering that the life of furniture, paint, upholstery and delicate textiles, as well as paintings, prints and other items that are sensitive to sun damage can be compromised as a result of sun bleaching.
Whilst curtains or internal blinds can be a solution, they have their limitations – becoming unsightly with age, fading as a result of sun bleaching, collecting dust and ultimately, with continued wear and tear, failing to work properly. The need to replace them regularly will inevitably result in a burgeoning cost and, as a result of discarding curtains and blinds, there is an additional waste to consider that will go to landfill unless they can be recycled for another use.
No sweat brise soleil
Almost all climates benefit from the careful diffusion and control of natural light to improve the quality and appearance of lighting during the day. Therefore, a logical solution to reduce the effects of solar gain, whilst affording the people inside the building continued enjoyment of an undisturbed view of the outside without disruptive glare, is the installation of permanent, secure, reliable, low maintenance and relatively low cost as well as aesthetically pleasing, brise soleil (Translated from French means ‘sun breaker’ or more accurately ‘to break sun’).
These systems can be made up of blades or take the form of solid shelves (or even walkways) and typically run either vertically or horizontally but can be completely bespoke, full façade feature structures integrated during the construction of almost any new building as well as many existing buildings. Brise soleil systems are manufactured from a variety of materials including timber, aluminium, steel, fabric, mesh, bamboo and Solinear’s new Resina product; a revolutionary natural fibre compound that has the appearance of wood but is more eco-friendly, highly resilient to the elements and needs very little maintenance. All these materials also come in a wide selection of colours from natural finishes through to red, yellow, green, blue and many other colours. The customisation doesn’t stop there; fixings should also be considered i.e. should they be visible and stand out or hidden so the brise soleil system appears to be floating in mid-air? Then there’s the finish – straight, circular, curved, motorised?
If expense is a concern then it’s worth noting that not only is the initial outlay cost-effective when compared with other façade screening or cladding systems, but brise soleil can provide a long term saving in running costs. A building that is equipped with this system will be less severely affected by the solar gain in the summer whilst retaining precious heat and sunlight during the colder months, meaning the end user will save money on air conditioning and heating costs thus protecting energy reserves and reducing the building’s carbon footprint.
According to the Carbon Trust, on a building with existing air conditioning, the amount saved on energy bills could pay back the cost of installing shading within 10 years. This is a reasonably conservative estimate and easily achievable. It’s based on installing fixed solar shading – i.e. brise soleil, on a 25m by 10m single storey, open-plan office building, which would cost around £6,000. Assuming an electricity tariff of 10p/kWh (including Climate Change Levy) and a 25% reduction in the use of the air conditioning (around 6,000kWh/year).
As new technology emerges, brise soleil is at the forefront of maintaining happy, healthy, low-energy-consuming, low-cost buildings fit for the future and as we become increasingly environmentally conscious, the demand for eco-friendly is going to be even more of a hot topic (no pun intended!)
What is brise soleil and why is it needed? The short version
- Buildings need to manage the solar gain and glare from continual periods of sunlight;
- Brise soleil systems consist of a series of angled blades to control the amount of light and solar waves entering a building, therefore they’re a practical, attractive and long-term solution to solar gain;
- Blades can be manufactured in a range of materials including timber, aluminium, steel, fabric, mesh, bamboo and wood-look composite in a variety of designs and colours;
- Advanced systems have motorised louvre blades that can automatically change angle in response to changes in sun intensity;
- Brise soleil systems are at at the forefront of maintaining happy, healthy, low-energy-consuming, low-cost running buildings fit for the future and add striking architectural features to a building as well as being practical.
Useful links:
https://buildingproducts.co.uk/uk-sees-increase-number-high-rise-buildings/
https://www.xperthr.co.uk/search/?keywords=recommended+temperatures+workplace
https://www.metoffice.gov.uk/climate
