Integrating window coverings into the overall plan for building designs has become an important consideration for architects, as aim for more hospitable, efficient environments. Window coverings are no longer an afterthought, but instead considered a building system just like HVAC and lighting systems.
This approach, called engineered shading solutions, considers well thought out window treatments as more then just a quick fix. In order to successfully control solar heat gain, glare caused by daylighting or levels of light into a space, architects know engineered shading solutions are a key part of the “dynamic facade” approach. A sustainable system of interior and exterior window coverings which engage the latest technologies can successfully achieve results in providing for the health, safety and welfare for the a building’s occupants.
Sustainable Design
According to American Institue of Architechts (AIA), “sustainable design is a collaborative process that involves thinking ecologically—studying systems, relationships and interactions in order to design in ways that remove rather than contribute stress from systems”. For example, there are countless situations of where poorly designed window coverings actually add stress to systems, such as floor-length draperies that block heating units, trapping the warm air. However, when done correctly, engineered shading solutions will successfully reduce stress from building systems. For a great example see this issue’s interview with architect
Roger Bayley, who specified automated exterior solar shades to reduce the solar heat gain into the rooms of the
Vancouver Olympic Village so the radiant cooling and heating system could function properly.
Additionally, there are examples of how engineered shading solutions can reduce stress as recommended by the U.S. Green Building Council. (USGBC) The following LEED strategies explain how window coverings can perform at equivalent levels as other sophisticated building systems.
Daylighting
Harvesting of natural daylight into a space is a priority of today’s design. However, the most common failure of this strategy is the glare caused by excessive light levels. Therefore, glare control is required and the USGBC recommends shades to remedy this stress. Engineered shading solutions can provide the technology to reduce
glare by as much as 95% with high performance fabrics.
Light Pollution Reduction
For projects to earn points for light pollution reduction, the USGBC requires that windows must have shades that are motorized and timed, thereby reducing the environmental stress caused by the nighttime spilling of light into the surrounding neighborhood.
Energy Reduction
The reduction of solar energy entering a space and thereby reducing the amount of energy used for cooling is
where engineered shading solutions perform the best. For example, exterior solar shades can reduce solar heat gain by as much as 85%.
Improving on the Past
Although there is a strong emphasis on modern technology, engineered shading solutions are not actaully a
new idea. Nearly 2,000 years ago during the height of the Roman Empire, the engineers of the Colosseum created a velarium, a retractable awning system that protected the spectators from the harsh rays of the Italian sun. While the actual means of how the awning was supported or adjusted are lost to us, the need and the concept
Interview with Roger Bayley
Vancouver, British Columbia was the home for the 2010 Winter Olympics. The Olympic Athletes’ Village, 
developed by Millennium Properties is Canada’s first truly sustainable community. The Olympic Village project is an example of how a contaminated industrial City center site can be transformed into a sustainable community.
The design manager for the project was Roger Bayley who worked with a team of five architectural firms to develop and implement the client’s vision. Today Roger leads his own firm located in Vancouver and is dedicated to sustainable energy solutions. It was my pleasure to speak with Roger about his role with the Olympic project and what directed the team to specify and install Exterior Shading Solutions.
NG: Why did you specify Exterior Shading Solutions?
RB: It came from the concept of heating and cooling the residential units with Germany technology using ceiling mounted radiant heating and cooling. This technology requires hot and cold water to flow through capillary tubes above the ceiling drywall. In our modeling, we realized that at certain high levels of solar heat gain into the space, condensation could result on the dry wall. The best way to reduce the solar heat gain and thereby eliminate the risk of condensation would be to install exterior solar shades. So the exterior solar shades became part of the energy equation.
NG: Can you explain the concept of the radiant heating and cooling system?
RB: Radiant energy transfers heat from a mass with higher temperature to one with lower temperature, in the neile way we are warmed by the sun. When the radiant system is switched to cooling, it draws heat from objects – including bodies – that are warmer, producing a cooling effect.
NG: How did installing the Exterior Shading Solutions contribute to achieving the LEED Gold designation?
RB: It was a part of the overall design that included the radiant ceilings, which enabled the project to earn points for Energy Efficiency and Innovation in Design. The entire project received LEED Platinum certification, and the buildings earned LEED Gold status.
NG: What performance capabilities did you require from the Exterior Shading Solutions?
RB: The project was complex. We needed a solution that could perform under adverse weather conditions, provide the energy reduction required, enhance the building’s exterior design and stand up to the test of time. The shades are controlled automatically with the combination sun and wind sensors. The components that include the side cables can withstand severe wind gusts and the fabric provides the solar protection needed. The design elements such as the enclosure and wall brackets enhanced the building façade.
NG: How do you see the future of sustainable building incorporating Engineered Shading Solutions?
RB: To begin with, shades cannot be an afterthought. They must be planned for from the beginning of the design stage. The key to an Engineered Shading Solution is automation and integration into the building systems. The shades need to be incorporated into the energy efficiency of the building. This requires good statistical data to prove the performance of the shading solutions. This is challenging to achieve at the outset of the design process.