Brise Soleil Explained
Building owners and architects have wrestled with the problems of direct sun exposure for millennia, struggling to balance the benefits and drawbacks of natural light and heat in their building designs. Blocking sun rays totally in a building creates a dreary, oppressive environment for tenants, offset only by the use of expensive, artificial light sources. On the other hand, exposure to direct sunlight escalates heat and glare – solar gain – fatiguing workers and leading to decreasing production efficiency.
Ancient builders recognized the importance of controlling exposure to the sun:
- The Greeks and Romans used large, movable cloth awnings known as velarium in ancient Greek theatres and Roman coliseums to protect patrons from the burning sun and occasional cloudbursts.
- Hindu builders used jalis – perforated stone or lattice screens in geometric patterns – to reduce the impact of direct sun, shade fixtures later copied by Islamic architects.
- The Japanese developed screens and blinds of horizontal slats of wood, bamboo, and other natural materials (Sudare or Yoshizu) to control light, heat and visibility, still in use today.
Most environmental scientists agree that future temperatures will be even hotter, more uncomfortable for humans around the globe, increasing the demand for sophisticated, affordable solutions to mitigate the damage of excessive exposure to the sun’s light and heat. Building owners, designers, and managers are returning to the proven solutions of the past, updated to capture the benefits of new knowledge, materials, and technology.
Shade fixtures – architectural screens – are available in a variety of designs, materials, colours, and prices. Brise soleil may be immobile or adjustable either automatically or manually. Shade screens can be incorporated in the original design of a building or retrofitted as a later addition, solving heat and glare problems.
The Origins of Brise Soleil
Charles-Édouard Jeanneret (1887 – 1965), aka Le Corbusier, is often credited with the popularity of brise soleil (“sun breaker” in French) in architecture today. One of his concepts, generally practiced by architects the world over, was the separation of a building structure components and its external appearance (the “facade”), leading to a boom in buildings of transparent and semi-transparent curtain walls of tempered glass, and unobstructed views for tenants.
Glass curtain-wall structures have many advantages, including transparency, weather-resistance, and colour variety. At the same time, the material traps heat, acting as a greenhouse driving up utility costs. Glare from the glass can be a significant problem for the building tenants as well as people in surrounding buildings. The Nasher Sculpture Center in Dallas, Texas, is currently suing the owners of a 42-storey glass-clad office building for multi-million dollars due to the building’s reflected sun and its effects on the art objects and visitors.
The problems of glare and solar gain precipitated a return to the age-old solution of brise soleil, updated, and adapted to function in the modern age. Architects exploited the capabilities of materials artistically and functionally, anticipating and preventing solar problems in new buildings and rehabilitating older structures to compete as if new construction.
Benefits of Architectural Screening
Building owners generally determine whether or not a project is successful by the rate of financial return on investment. In practice, profits are the difference between income (occupancy and rental rates) and expense (initial construction, utilities, maintenance, and taxes). As a consequence, building owners seek to position their property as unique, subsequently attracting tenants who will pay high rents while keeping costs as low as possible.
Architectural screening provides critical benefits to owners, including
- Lower construction costs. Using a building facade is less expensive and more adaptable than using exterior walls to ensure structural integrity.
- Lower utility costs. Eliminating a significant percentage of heat gain reduces the costs of cooling a building to accommodate tenant comfort.
- Reduced internal and external glare. A series of external vertical or horizontal sunscreens block a designed percentage of the sun rays that attack a building exterior and often penetrate beyond glass barriers. They also reduce direct reflections of the sun to surrounding areas that often result in an additional cost to mitigate.
- Distinctive appearance. Because architectural screens or louvers are attached externally, they can be removed and replaced with minimal cost and time. The flexibility of design and variability of construction materials ensures that the building’s appearance is always updated and unique, a key marketing position for most owners.
- Noise reduction. Noise pollution is a growing problem in urban areas around the world. The number of cars, electronic devices, and machines required for work and home life produce noise levels that are harmful to health. Studies in recent years link high ambient noise levels to a variety of health problems, including stress, sleep disturbance, and impaired cognitive performance. Architectural screens or baffles significantly reduce the levels of ambient sounds entering a building.
Modern Versions
Solar screens and louvers are available in aluminium, stainless steel, galvanized steel, timber, perforated mesh, and space-age fabrics depending on the purpose of the fixture and the creative intent of the designer. No longer limited to straight vertical and horizontal lines, professional designers and manufacturers create custom screens and louvres in multiple sizes and shapes that function effectively to lower sun and noise exposure while adding visual drama to the structure.
Design, Manufacturing and Installation Considerations
Each use of brise soleil is unique due to the building owner’s intent, site, size, and condition of the building. Capturing the intended benefits of the fixtures requires
- Precise design specifications. While utility and appearance are critical, the safety of the public is the paramount objective of every building owner. An exterior sunscreen or louvre system relies on exact engineering calculations to perform safely and as expected.
- Exacting manufacturing tolerances. Brise soleil fixtures are complex fabrications that function in all environments. Errors during the manufacturing stage invariably complicate and may compromise the structural integrity and stability of installed screens or louvres.
- Professional, experienced installation. The effectiveness of sun- and noise-blocking systems depends on the proper alignment and attachments of screens and louvres. The work often necessitates the use of large, mobile industrial machines working at great heights to make connections between a building and the fixture.
Final Word
Successful building owners, whether the long-ago managers of the Roman Coliseum or a modern apartment building in London, understand that appearance and tenant comfort directly impacts the financial success of real estate projects. The addition of custom architectural screening or louvres can make a copy-cat structure visually unique and reduce glare, heat, and sound irritants that dismay potential tenants.
