Volume 49, Issue 7 - July 2014

feature

Out of the Box
Advancing Façade Developments Call for a New Way of Thinking
by Ellen Rogers

The idea of collaboration always sounds good on paper, but for those in the building envelope industry it can sometimes be a challenge to bring multiple parties together early on in the design process. The rapidly evolving technologies and increasingly stringent regulations may soon bring advanced façade developments to fruition.

“It’s like what we were going through seven or eight years ago. It was unimaginable there would ever be any other smart phone device other than Blackberry,” says Attila Arian, president of Schuco USA LLLP. “But people saw a trend [in changing products] and they reacted. It’s the same thing in the glazing industry.” Three-D designs, Arian says “have changed the way we deliver a project. If we don’t react and become a part of it we may be left out. If we don’t, we may be out of business. [The industry needs to work toward] a joint effort in technology.”

So, just how, exactly, are façades evolving? The industry is seeing a transition from static façades to ones that are dynamic. These changes are driven primarily by a need and/or desire to control heating and cooling costs, as well as ensure occupant comfort. At the same time, technologies are making it possible to design and build increasingly geometric buildings.

“People don’t want to be in boxy square buildings anymore,” says Arian. “The architect’s expression has become more drastic. People are looking to make a statement with buildings.” Glass has a significant role to play in the development of these advanced façades, increasing the need for more education, knowledge and collaboration.

“The technology involved in dynamic façade solutions is challenging from design through installation,” says Mic Patterson, with Enclos’ Advanced Façade Studio in Los Angeles, “and these projects are most successfully done under a design-assist project delivery strategy that accommodates the very early participation of key suppliers, contractors and consultants.”

"High-performance façade systems are challenging enough in themselves. Requiring them to move increases the complexity tenfold, and this must be reflected in the cost."
—Mic Patterson, Enclos

Movers and Shakers
If the days of the boxy, simple structure are behind us, where, then, is this new age of building façades headed?

“If you think about curtainwalls in buildings today, normally you find a static, fixed structure with lots of glass. In media images of architectural spaces the views from the windows are typically clear and unobstructed,” says Stephen Selkowitz, who works in the Building Technology and Urban Systems Department in Lawrence Berkeley National Laboratories. “In the real world that does not always work, especially with a highly glazed curtainwall, because glare, solar gain and privacy will dictate some form of management. So occupants try to control these impacts with shades and blinds, but they don’t reliably do a very good job of it. For example, blinds are lowered on the east to control morning sun and glare, and then never raised during the day. And architects hate the random appearance of blinds/shades closed or open.”

Patterson adds that the term “dynamic” is a good counterpart to the term static.

“Interactive/intelligent façades are often referred to as dynamic, meaning that they change in behavior or form in response to some stimulus,” he says. “Electrochromic glazing materials, for example, can vary light transmission in response to an environmental or user-provided stimulus. In this case, nothing moves. Kinetic façades (see below) are a subset of dynamic façades, in which elements of the façade actually move.”

Of course much of the growing interest in façade materials, such as the electrochromic glass and integrated shading devices (see sidebar on page 61) is a response to increased demand for energy reduction and occupant comfort.

“If you want to use a lot of glass for view and other market reasons, the reality is you need control over the properties of the curtainwall,” says Selkowitz. “The most important step, in my opinion, is that the curtainwall needs to be designed and operated dynamically. Think about the variability between winter/summer; day/night; sunny/cloudy, etc., in terms of temperature, energy, glare and light. So the idea that a fixed/static wall will be perfect in all conditions simply does not make sense.”

The envelope, then, should be dynamic in order to accommodate all the ranges of activity going on outside and inside. But how is this accomplished?

“The good news is that there are a myriad of options on the technology side. You can change the glass (i.e., use electrochromic glass) or use external, between-the-glass, or internal shading devices, for solar control and daylight management. The key is you’re adding a layer of dynamic control to what historically has been a fixed element,” Selkowitz says, explaining that the questions then become how are these systems operated, by whom and when? For private offices and some small buildings Selkowitz notes that well designed manual controls may work well, but for open office space where occupancy varies and in larger buildings he believes the future belongs to smart controls.

“This gets into the realm of automated, intelligent control,” says Selkowitz. “If you want to optimize energy performance of the window throughout the year and you cannot consistently rely on a person, then you want a “smart” system to assess conditions and respond appropriately. You will need sensors to gather data and conditions and “actuators” to control glass transmission, blind position and light output in response to what’s going on inside and outside the building. I’m convinced this can be done reliably and unobtrusively, and will improve comfort and performance as well as reducing energy use. ”

He adds, “In many commercial buildings the single largest energy end use is lighting while the largest peak electric load comes from cooling. So we want to control the solar gain coming through the window; but also manage the curtainwall for adequate daylight. You need to let enough daylight in to reduce electric lighting, but not too much because you don’t want to create glare. It’s a challenge to continuously adjust all of this; which is why we propose automated controls to balance daylight savings with management of glare and cooling loads. This becomes a moderately complex problem that needs reliable, cost effective solutions, which fortunately are available.”

Arian has seen interest in bringing integrated photovoltaics into the façade. One example he gives is work being done by the company HeliOptix.

“They are essentially creating lenses that move through a sensor,” says Arian. He explains the technology can be used to reduce solar heat gain by about 80 percent while generating electricity at the same time.

The company’s ICSF System, for example, is described on its website as “the first architectural daylighting system integrated with concentrating photovoltaic solar cells that will substantially reduce overall energy consumption for buildings and provide facilities owners with a short-term payback.”

Market Acceptance
Just as façades become increasingly dynamic, they also become more complex.

“Static façades are a challenge in themselves,” says Patterson. “Layer on the systems integration, kinetic elements, innovative materials, and novel products that often accompany a dynamic façade, and the complexity can easily escalate by an order of magnitude. This impacts cost, of course, and this becomes the biggest barrier to integrating dynamics into the building skin.”

Adding to this, he says cost can be a significant concern.

“High-performance façade systems are challenging enough in themselves. Requiring them to move increases the complexity tenfold, and this must be reflected in the cost. Even something as basic as operable vents represents a challenge, which is why they are so often excluded in high-rise office building design.”

Arian agrees that the biggest challenge is cost.

“In Europe buildings are built to last 60-100 years. In the U.S. they are built to last 25 years and everything is cost-driven. Every new product you have has to be prepared for economies of scale and this has been a big problem in the U.S. … [Either the] budget is not there or the owners are not willing to spend the money. It takes courage and takes money [to build these façades],” he says, explaining he most commonly sees such an installation on a university or private building.”

National policy and regulation are also drivers in Europe.

“We can look for other examples where investments are being made in high performance façades,” says Selkowitz. “In Europe the governments have consistent policies to push energy efficiency and carbon reductions, so investors, owners and design teams think about energy efficiency as a major design driver. Energy costs are also much more expensive there. So when policy is reinforced by fiscal realities it results in building designs and façades that are more efficient. Owners value the increased performance (comfort as well as energy) and are willing to put more investment into a high performance envelope and less into the HVAC and monthly energy bills.”  

Patterson adds, “We are burdened in the U.S. by cheap energy prices and lax building codes. We simply don’t have the performance drivers in our domestic market that exist in European markets.”

He continues, “We hear a lot from vested interests that more aggressive building codes will negatively impact our sector economies, while quite the opposite is true. The legislated mandates for dramatically improved energy efficiency in European buildings in the wake of the 1970s oil crisis drove their façade technology probably two decades ahead of ours. We are only now beginning to catch up.”

Another reason, according to Arian, that the North American market is slower to embrace such technologies involves the legal liability the owner takes.

“People are afraid to be sued,” he says, “And in the U.S. people overdesign and engineer to be 100-percent sure it won’t fail so the risk of liability is somewhat managed.”

Benefits at Best
Yes, advanced façades present challenges and yes they are expensive. However, they can also bring significant opportunities for both building owners and occupants. Capitalizing on this is crucial for the glass industry.

Patterson adds, “The opportunity for the glass industry is to help the design community produce more efficient façade systems, combining relative economy and absolute performance. Balancing the many, often competing, considerations that merge at the building skin has become an increasingly sophisticated and challenging problem, and one that the design community is struggling with.”

He points out that when another recently completed LEED certified glass tower is revealed as an energy hog, glass often gets the blame. “This is bad for the entire building industry, and certainly represents a threat to the glass industry. It’s a threat that can be addressed with education, but only at the very highest level, and involves investment in research and development because the required tools and techniques do not all exist.”

Designing and constructing an energy-efficient building is not a luxury. Arian adds, “The industry must learn to build in energy-efficiency, high-quality systems. We all need to be thinking about this. Energy-efficiency is not just an idea it will impact us all drastically on multiple levels.”

Ellen Rogers is the editor of USGlass magazine. Follow her on Twitter @USGlass and like USGlass on Facebook to receive updates.


Statement Pieces
In addition to becoming more dynamic, façades are also taking on unique forms. This, according to Attila Arian, president of Schuco USA LLLP, goes back to architects and owners who want to make a statement with the building. As a result, his company has developed what’s called the Parametric Façade.

Arian explains that Parametric Façades are the company’s “first stab at providing an integrated system that optimizes design and energy efficiency while giving the architect the utmost flexibility when it comes to form and functionality. It follows the concept of the structural modeling, where algorithms are used to improve function and design.

“It is essentially a vertical unitized shell consisting of nods and members that allow unusual geometries based on 3-D designs, flexibility in design and scalability of fabrication through the application of modeling software in combination with standardized aluminum systems that allow for more unusual designs and not just squares and boxes.”

He continues, “I think when you look at designs becoming more complicated today there is also a need to look into digital fabrication—a setting that will allow you to fabricate right of off the 3D model in economic ways, granting the freedom to design [unique] entities … We all have to work harder to come up with unusual designs and be prepared for a tight budget.”

As a result, Arian says he’s also seen increasing use of Building Information Modeling (BIM) tools.

“Three-D modeling and BIM have changed the whole industry, creating a different environment. Companies are modeling entire jobs in the bid phase and doing estimating and take-offs based on 3D models. Once they are awarded they can hit the ground running.”


Kinetic Reaction
Kinetics, in a traditional thought process, is the science and study of the human body’s movement. Some in the architectural industry have taken that term and given it a new spin. The term “kinetic architecture” describes façades, for example, that move or change to adapt to seasonal, functional or daylight requirements.

According to Mic Patterson, with Enclos’ Advanced Façade Studio in Los Angeles, there is currently a great deal of interest in kinetics.

Russell Fortmeyer, LEED AP, a design journalist, electrical engineer, and sustainability consultant with the LA office of global engineering firm, Arup, and Charles Linn, an architect who has specialized in architectural journalism for the past 25 years, recently authored the book, Kinetic Architecture. Through the use of various case studies, the book explains “how complex multilayered façade systems create energy efficient, architecturally distinctive, and sought-after places to live and work.”

Likewise, Patterson adds, “At Enclos, we have launched a division we are calling Enclos Kinetics that is already involved in implementing a number of projects involving operable elements.”


Is North America Ready for Integrated Glass Shading?
The incorporation of advanced shading into insulating glass units (IGUs) may be more prevalent in Europe than it is in North America and, while market barriers, such as cost do exist, the technology may also present a growth opportunity here.

“I think the big advantage is that IGU shading is geometric,” says Erik Olsen, managing partner at Transsolar Inc., a consultancy that brings engineering expertise to architecture, specifically on energy matters. “Any kind of geometric shading device is always higher performance” than a coating-technology product, he explains.

Viviane Chan, director of sales and marketing at Unicel Architectural, echoed that point. Aesthetics aside, the most effective means of controlling solar impact, both she and Olsen say, is to place the barrier on the outside; the least effective option, meanwhile, would be to place it on the inside (e.g., traditional blinds or shades), allowing heat to penetrate the glass and get inside.

But then there’s the third way, via the IGU. “I’d say those types of products are not extremely widely used [in Europe], but they’re certainly more commonplace and more available than they are in the U.S.,” said Olsen.

External shading is often not a preference of architects for aesthetic reasons. But with IGU integrated shading, designs can maintain a “smooth, glassy skin,” as Olsen says, to the exterior of the building.

Is the North American market simply unaware of the availability of such offerings? “Architects are aware that these products exist, but there are a lot of other ways to control light,” says Chan, citing various options such as diffused daylighting systems and translucent panels.

Much of the barrier, then, comes down to cost. Unicel’s factory is in Quebec, but many other manufacturers are located in Europe, requiring U.S. customers to absorb the cost of importing, not to mention the product cost itself.

Nevertheless, Transsolar recently worked on a project at Princeton University that employed the use of DLS Coolshade, a product from Eckelt Glas GmbH, for a skylight—a limited application, thus containing cost.

These systems also are effective for certain applications that address solar-oriented goals, says Chan. “One of the advantages is that you can use them for overhead glazing and anything in a slanted or angled position such as skylights,” she says.

That’s because basic, older-generation IGU shades can sag, whereas other products that incorporate extruded aluminum louvers never touch the inside face of the glass, Chan says.

So, is there market potential here in the U.S.?

“The potential for using that kind of product is tremendous,” says Olsen. “The issues are availability and cost—which are always the two issues.”
—Carl Levesque

 

 

 


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