FabricArchitectureMag.com | May 16, 2012

By Jonathan Kalstrom

The design, applications and mechanical systems of air structures have continued to evolve. Among the noteworthy recent developments in the industry are enormous clearspan air-supported structures and mobile air-inflated structures, both products of innovative designs. Efficient mechanical control systems that automatically respond to environmental conditions provide reduced energy costs, as do double-wall fabrics. And, among the applications are indoor golf driving ranges, multi-purpose sports facilities, industrial warehouses, construction-site enclosures and exhibition halls.

One such air structure, an exhibition hall, was unveiled in October 1996. Designed by Festo AG & Co. KG, Esslingen, Germany, it is the first building in the world to be constructed with a cubic interior comprised of supporting structures built with air-inflated chambers. “The basic idea is to use it for mobile exhibition purposes,” says structural engineer Hans-Joachim Schock of Festo. He notes that the inflatable structure can be packed into one 4.25m container.

The load-bearing structure of the hall, which includes 40 Y-shaped columns and 36 wall components along both longitudinal sides, offers a variety of new features: double-wall fabric that acts as a load-bearing element, flame-inhibiting elastomer coatings and a new, translucent ethylene-vinyl acetate coating. “We have used some materials which have never been used before in this context,” says Schock, including EVA-coated fabric, which provides high translucency in the roof structure.

This air-inflated structure responds to environmental forces so the pressures in the different elements are increased in the cases of high wind or snowfall, Schock explains. Columns, arranged in the shape of a saw-tooth pattern, along with pairs of wall components, carry vertical and horizontal loads, such as snow. The horizontal wind load is carried by the frame and by elastic tension elements or “muscles.” When wind hits a side wall, the muscle elements contract. The computer-controlled muscle-elements, an innovation of Festo, are made of polyamide fabric with an internal silicone base. The horizontal girders, or air beams, contribute to the stability of the structure.

The structure requires a small, but continuous amount of energy that is provided by a pressure supply system, according to Schock. One advantage of this type of structure, he notes, is its thermal insulation.

The ability to provide an R-12 or better insulating value in air structures is an important development at Yeadon Fabric Domes Inc., St. Paul, Minn. “Typically an air structure has an R of 2 [or] 2.2 maybe,” says Yeadon’s technical services manager Milosh Nadvornik. “With our system, we can enhance that to an R-12.” The advantage of having higher R values is that it keeps warm air inside in the winter and cool air inside in the summer, resulting in lower energy costs, Nadvornik explains.

“It’s the biggest thing, most likely, that’s hit this whole industry in 20 years,” says Peter Donoghue, general manager and secretary treasurer of Yeadon. “The insulation just brings the energy costs down to something very reasonable.” Yeadon manufactures both permanent and seasonal air-supported structures for such sports applications as tennis, golf, football and hockey. Yeadon, for example, constructed a 110m multiple-sports structure in St. Paul, Minnesota, that covers a city park in the winter and is taken down in the spring.

“The market has required bigger, larger, wider structures which has caused us to look at and come up with new designs, new cabling and new ways of doing them,” says Donoghue. “The concern about energy costs has allowed us to come up with mechanical systems—inflation and heating and air conditioning—and the controls to run them that are state-of-the-art at the present time.” Yeadon has developed an integrated system that houses everything from backup blowers and air conditioning coils to the heating component in one box, Nadvornik says. Automatic controls for inflation and pressurization of the dome present energy savings. “You used to have to adjust manually any time the wind came up, you had a snow condition or a storm approaching,” Nadvornik says.

The increased size of the enclosures is another development in the industry. “We’ve gone from the little tennis bubble or swimming pool enclosures to the huge complexes that encapsulate the activities, whether its soccer, football, lacrosse, running track and so on,” says Jan Ligas, technical sales manager for Air Structures American Technologies Inc. (ASATI), Rye Brook, N.Y. The transition in the industry to the golf dome and multi-sport arena started in about 1990, according to Ligas. In the early 1980s, company CEO Dan Fraioli develop his first trapezoidal-shaped, multi-height air structures for indoor golf driving ranges. “We were pretty much 10 years ahead of the market with the demand—golf really started to take off in the late ’80s and early ’90s,” says Ligas. He adds his company’s golf domes have been “a tremendous success, and it’s created a boom to our industry.”

A typical golf dome is about seven to eight stories high and has a driving distance of roughly 90m, according to Ligas. He notes that his company makes efficient use of space in the golf domes because as the ball travels, the building tapers. “So, if you were 76m wide at the area where you’re driving from, the building actually becomes 38m wide at the far end,” Ligas explains. One reason the company became involved in this niche, he says, is that in certain geographical areas the weather limits golfing to only three or four months a year.

Golf domes are just one type of structure that ASATI has focused on. It is also involved in multi-sports facilities, as well as industrial applications such as warehouses and multi-acre construction-site enclosures. Because of the popularity of soccer in particular, most large facilities are becoming multi-functional for such sports as soccer, golf and softball.

Because ASATI has developed a patented cable-stress release system, it can erect clearspan buildings ranging from several hundred square meters up to 6 or 8 hectares [15–20 acres], if necessary. For example, ASATI constructed a facility for a chemical company in Corpus Christi, Texas, considered the world’s largest ground-mounted air structure at about 2.36 hectares [5.9 acres] clearspan. As a result of the cable-stress release system, the fabric does not recognize the size of building to which it is attached. Whether it’s a small 450m² building or a 45,000m² building, the loads on the fabric are relatively the same, Ligas explains.

The future for the air structure industry looks bright. Ligas says that the air-structure applications he described will become even more popular in the future. “It’s just the beginning,” he says.

Jonathan Kalstrom is president of Jonathan Kalstrom Remodeling & Design in Minnesota.

Editor’s note: This article appeared in the May/June 1997 issue of Fabric Architecture (then called Fabrics & Architecture).

Learn how technical fabrics can aid acoustic control. Discusses reflection, absorption coefficients; design solutions and case studies. Online testing.

More details in the near future. In the meantime, check out other continuing education stories.

Fabric Architecture magazine provides the opportunity for CE credits by partnering with the Fabric Structures Association of IFAI, an official provider of the American Institute of Architecture (AIA) Continuing Education System (CES).

FabricArchitectureMag.com | May 9, 2012

The American Institute of Architects (AIA) and its Committee on the Environment (COTE) have selected the top 10 examples of sustainable architecture and green design solutions that protect and enhance the environment. Projects showcase excellence in sustainable design principles and reduced energy consumption.

One of the top 10 awarded projects is the Arizona State University (ASU) Polytechnic Academic District, Mesa, Ariz., designed by RSP Architects and Lake Flato Architects, which features fabric shading elements as one of the designers’ palette of strategies for reducing energy use and promoting sustainability.

Project design team leader for RSP, Beau Dromiack, described the thinking behind their use of specialty fabrics for shading a key portion of the campus buildings: “For the most prominent building of a trio of academic buildings, the highest balcony of the tallest building has a wall of translucent fabric that shades the open air student space and actually makes it habitable during the hottest time of the Arizona year.” This promenade is integrated with a latticework of glass and PV modules that feed energy back into the college electrical grid. Also helping the overall carbon footprint is the attachment of vertical fabric scrims between windows on the facades of the classrooms and offices facing east and west.

The design for the Polytechnic Academic District transformed a decommissioned airbase into an inviting pedestrian campus that includes five high-performance LEED Gold rated buildings. The design for the new campus creates a new identity that responds to its desert climate and context by using a dense network of linear buildings that maximizes shade and creates a vibrant pedestrian environment. The building typology grew from the same objective by extroverting the circulation which also served to minimize the air-conditioned square footage and electricity for lighting.

All 10 of the projects will be honored at the AIA 2012 National Convention and Design Exposition in Washington, D.C. later this month.

The Smithsonian’s Cooper-Hewitt National Design Museum has announced the 2012 National Design Award finalists. The awards recognize excellence across a variety of disciplines. Award recipients will be honored at a gala dinner this fall at the 13th annual National Design Awards program.

A jury of design leaders and educators from across the country reviewed submissions resulting from thousands of nominations submitted by the general public. Included as a finalist is Clive Wilkinson Architects for the Interior Design category. Clive Wilkinson Architects is a distinguished architecture and design practice based in Los Angeles, which collaborates with clients to design and build creative communities. The practice has completed creative projects across the globe for clients such as Google, Nokia, 20th Century Fox and Disney, winning more than 75 awards in the process.

Clive Wilkinson Architects have produced a number of innovated designs that incorporate architectural fabric, including the Pallotta TeamWorks warehouse offices featured in the March/April 2004 Fabric Architecture magazine, and the Fashion Institute of Design & Merchandising, Los Angeles featured in the January/February 2011 issue of Fabric Architecture magazine. Both projects were done in collaboration with J. Miller Canvas.

More information about the Awards on the Cooper-Hewitt Museum website.

Fabric Architecture | May 2012

By Mark Zeh

Recently, the “Rescuing Hand” helicopter landing platform at the University Hospital Aachen was named “Building of the Week” by the German e-magazine german-architekts.com. This striking structure, designed by OX2 Architekten of Aachen, Germany, marries a wide variety of construction technologies and materials in its form, with membrane technology taking prominent place. I had the opportunity to talk with Marcin Orawiec, one OX2’s founders, about some of the design decisions and construction challenges the firm faced to create this structure.

Mark Zeh: The helicopter landing platform exhibits several different surface materials and fabrication techniques. How were they selected?

Prof. Marcin Orawiec: The funicular portion is clad in duraskin® B18039, a PTFE-coated glass fiber material from Verseidag-Indutex GmbH. We selected their material since it’s one of the very few that is both fire class A2 rated and capable of resisting the high tension under which the membrane is placed. The green passage portion of the structure is clad in steel as we were not able to print the pattern and color combination we’d designed onto this type of membrane. The pattern and color play are based on the interior floors of the clinic.

MZ: The membrane portion is amazingly free of wrinkles or tension lines.

Orawiec: The membranes are under a very high level of tension—about three tons per meter around the perimeter. The planners for the structure, stahl + verbundbau GmbH, Dreiech, Germany, employed Ceno Membrane Technology GmbH, Greven, Germany, to install the membranes. The installation process was quite involved and took about three months to complete. After the steel construction was complete, Ceno Membrane Technology took very accurate measurements of it, then created the cutting patterns for the mounting rails and membranes. Mounting each individual membrane took about two weeks. During this time, the membranes had to be placed under constant tension, then re-tensioned every two to three days. As a result, the membranes relaxed about 1.4% (20cm over a 14m span). At that point, they had reached a point where they could be permanently mounted.

MZ: How did you go about formfinding?

Orawiec: We created the initial form, using Rhino software, then sent it to the engineers for evaluation. A series of these iterations took place before we reached agreement on the final form of the structure. We’re satisfied to say that the result is 98% of our original proposal.

The helicopter landing platform was opened for service in July 2011. Construction costs were 7.5 million euro.

Editor’s note: This project was first reported in FA by Mark Zeh in the May/June 2010 issue.

Munich-based contributing editor Mark Zeh writes frequently about design and innovation.

By Jan M. Brenny

PUMA®, the sport and lifestyle company, wanted a practical and high profile venue when it enlisted Inflate Products Ltd., a U.K.-based manufacturer of inflatable fabric pods, cubes and domes, to design a temporary structure for use at the Volvo Ocean Race. PUMA sponsors an entry in the round-the-world sailboat competition and sets up temporary brand venues in each of the 10 pit stop port cities. This project, dubbed the PUMA Social Club, “was supposed to be a casual and chill place to hang out,” explains Nick Crosbie, founder of Inflate. “There would be a bar and other activities to attract the young and the hip.”

“[PUMA] wanted the design to complement what they had,” he says. “They wanted something big enough but also something that could be packed down smaller than the containers.” PUMA settled on a structure that can be set up in four days, taken down in two to three, and once down, all components fit into three open-top, 12m containers.

Inflate had worked with PUMA before, supplying temporary structures at a number of events in the U.S. and U.K. PUMA initially expressed interest in the Airflow line of stitched-together inflatables, constructed of PVC and ripstop nylon that require continually running inflation fans because air leaks through the seams—hence the name Airflow, Crosbie explains. It’s one of several pneumatic systems offered by Inflate.

The company’s newer AirClad design, produced by a division of the same name, is a sealed system intended for more permanent installations. The fabric is high frequency welded and fans run only when necessary—typically about 10 seconds every 20–30 minutes, depending on the weather, Crosbie says.

Instead of the sport/garment-grade material supplied to Inflate by factories inChina and Malaysia for Airflow structures, the design team chose France-based Serge Ferrari’s 501 PVC-coated polyester for the AirClad project. Because of the more technical, architectural nature of the fabric, “it was ideal,” Crosbie says. “Able to withstand high-tension, high-pressure inflation, and it’s longer wearing.”

Inflated fabric cells, constructed out of 225m² of the rain- and dirt-repellent material, stretch down the sides of the PUMA Social Club’s steel subframe. “Inflation gives the structure extra tension and lateral strength, as well as increased insulation,” Crosbie says. Gray-tinted glass panels adorn the front and rear exterior walls. The panels, juxtaposed with the inflatable cells, make the building “look sort of like an iPad®,” Crosbie notes.

The club measures 135m² and can comfortably accommodate about 100 people. A rooftop terrace of the same dimensions, accessible by an exterior staircase, offers visitors a great view of all the port-side race happenings.

Jan M. Brenny is a freelance writer based in Minneapolis, Minn.

The main lobby of the new W Hoboken Hotel and Residences, Hoboken, N.J., sends a modern and sophisticated message to guests with a floor-to-ceiling metal mesh façade framing the welcome desk. Flexible stainless steel metal fabric panels wrap the entire lobby wall and reflect cool purple-colored light back to visitors seeking accommodations, nightlife or a chic resting spot between meetings.

The metal fabric system—from Cambridge Architectural—features a new attachment method, allowing metal fabric panels up to 18m to be installed in tension, but much closer to the wall, using the unique Micro-Eclipse attachment system. Custom-cut apertures receive the metal fabric ends in tubing integrated into a bracket and structural support design, with tube sizes appropriate to emphasize or conceal the attachment, as the design dictates.

The Jamsil indoor swimming pool in Seoul, South Korea, hosted the Asian Games in 1986 and the Olympic Games in 1988, but fell on hard times. The Seoul Metropolitan Government graded the facility a “D” during a 2010 safety inspection. Enter Hanwha Polydreamer, a Seoul producer of PVC and PVC-coated products.

By installing a UniTent low-shrinkage, high-tenacity polyester membrane roof structure inside the Jamsil indoor pool, Hanwha Polydreamer helped the city of Seoul reduce construction, heating and air-conditioning costs while improving safety, at a revised cost of $4.5 million (compared to an original estimate of $25 million).

The world’s largest indoor theme park gives visitors the chance to experience fast and furious fun, Ferrari style. Ferrari World, on Yas Island, Abu Dhabi, takes the legendary Italian sports car to new speeds, with a family-friendly attraction offering rides, films, shops, restaurants and lodging, accented in red and steeped in all things Ferrari. The client wanted existing internal walls to mimic an air intake system of the iconic car through a series of fabric “fins.”

Fabric Architecture Ltd., Gloucester, U.K., rose to the occasion by designing and manufacturing 2,063 tensile wall-mounted façade fins to dress up the theme park.

Fins are mounted to every internal wall façade, and each is unique, varying in size from 5m to 20m in length. The fins are constructed from extruded aluminium clad in tensioned silicone glass weave fabric (an estimated 45,000m²). The glass weave fabric allows 40% light transmission, allowing the fins to reflect and transmit LED lights and video. The fin array follows the curvature of all internal buildings, conceals building utilities, reduces noise and commands considerable attention from visitors.

Fabric Architecture | May 2012

By Mark Zeh

One of the enduring visions in the use of membranes and fabrics in architecture is that structural volumes can dynamically respond to people and the environment. This vision is of buildings that can expand, contract or otherwise change shape for different uses and allow weather and light in as desired.

There are three basic categories of these dynamic types of membrane structures: adaptive, kinetic and convertible (most common).

Projects such as the 1996 “Airquarium” Airtecture Display Hall from Festo, which could adjust its stiffness in response to environmental loads, and the 2001 GINA concept auto from BMW Group Design, are examples of different types of adaptive structures. These applications show how membrane technology can allow forms and surfaces to change, depending on what outcome is desired.

Kinetic membrane structures are those that change shape, or move, to evoke a response. They are most often seen as art or concept pieces. One example is the 2001 Expo.02 Nouvelle DestiNation in Biel, Switzerland, by Eckert Eckert Architekten of Zrich, in collaboration with the German artist Via Lewandowsky, which continually altered its form as a way of engaging visitors in a dialogue about politics in Switzerland. Another example is the 2003 GEK Balance Roadshow, designed by Schienbein + Pier GbR of Stuttgart, Germany. This demountable membrane structure was designed to give attendees the experience of traveling through the interior of the human body. It was composed as a reconfigurable modular structure of organic volumes, because it had to be assembled in many different venues.

A structure such as the National Stadium in Warsaw, Poland, from gmp (von Gerkan, Marg and Partners) of Germany, built for the 2012 UEFA cup, embodies state-of-the-art design and construction of convertible structures. According to gmp, it is the largest flexible roof in the world. It consists of a complex, tensioned cable-supported 55,000m2 PTFE/glass fixed membrane roof with an 11,000m2 PVC/polyester fabric retractable roof at its center.

Another convertible roof example is the 2003 Giesshalle H01 in the Landscape Park Duisburg North in Duisburg, Germany. This structure was rebuilt as weather protection for open-air events during the Ruhr Triennale by planinghaus architekten bda, of Darmstadt, Germany (opposite). Uwe Burkhardt, of Schlaich Bergermann und Partner, explains that since PVC/polyester, a material that can be folded, did not meet the transparency requirements of the design team, the solution created used pressurized ETFE cushions in metal-framed “carts.”

A long history of development

It is worth exploring why convertible roofs are, by far, the most-commonly seen dynamic type of membrane structure. This type of roof has the longest period development: Retractable sunshades in amphitheaters and stadia antedate by some time the velarium at the Roman Colosseum. Modern structural techniques and materials have enabled this concept to evolve from that of a retractable sunshade into a retractable fabric roof that shields against weather and can be opened to sunlight and fresh air. Development in the last 30 years has been amazingly fast, providing obvious benefits for event promoters, facility owners and the public.

Why haven’t we seen a similar push toward “design maturity” in the other two categories?

“I think most architects have lots of these ideas in their sketchbooks,” says Tim Hupe, founder of Tim Hupe Architekten in Hamburg, Germany,“but membrane projects with dynamic components can’t be attempted without a really great engineering partner, and the project costs are usually high.”

“There really are only a handful of companies that can engineer a dynamic membrane structure,” says Prof. Dr. Jan Cremers, director of technology for Hightex GmbH of Rimsting, Germany. “Also, architects who haven’t been taught in membrane architecture need to do quite a lot of work to understand the technical constraints of the technology.”

Many challenges

Several room acoustic solutions using membrane materials are on the market, from companies such as Birdair Inc. of Amherst, N.Y. and Koch Membranen GmbH of Rimsting, Germany. However, sound transmission through membranes remains a major challenge.

“High frequency sound is reflected by many materials used in membrane architecture,” explains Dr. Rosemarie Wagner of the Karlsruhe Institute of Technology, Germany. “But low frequency sounds pass through most membrane walls with little attenuation. You can see an example of how this problem can be resolved at the Bangkok airport, where an additional layer of fabric was suspended beneath the membrane roofs to trap the low frequency sound from the jet engines.”

Another challenge is energy loss through membrane materials.

“The materials are quite thin, so there isn’t much opportunity to provide insulation value,” says Wagner. “Much current work on this problem focuses on different methods of capturing solar energy, storing it and releasing it when temperatures are lower.”

Another approach has been taken by Birdair Inc., which is offering a material called Tensotherm™. This material is a sandwich, consisting of an external skin of PTFE/fiberglass, a middle layer of Lumira Aerogel material, and an inner layer of either PTFE/fiberglass or a vapor barrier material. This composite material promises to add insulation against heat loss and sound while providing high levels of translucency.

A further challenge is in designing openings in membrane structures. This isn’t so important for large roof projects, but for applications on the scale of even a multiunit dwelling, there must be robust, well-designed solutions for windows and doors.

Dr.-Ing. Walter Haase, of the Institut fr Leichtbau Entwerfen und Konstruieren (Institute for Lightweight Structures and Conceptual Design), or ILEK, at the University of Stuttgart, Germany, is one of the people working at the forefront of research in these types of applications and problems.

“It is worth remembering that the initial design problem behind the development of current membrane architecture was the development of wide span roofs,” says Haase. “Frei Otto and his colleagues were principally concerned with creating lightweight solutions to enclose large spaces, but now energy consciousness and other design problems have entered the picture.”

New materials, new designs

A few of the ILEK’s recent projects in adaptive architecture are particularly notable. The first is an experimental application of Aerosil® (nanoporous high insulating pSiO₂) and Phase Change Materials (PCM).

“Our prototype, ‘paul,’ [by Markus Holzbach] was built to demonstrate a few effects. The first is the potential insulating value that can be gained by using Aerosil materials in a multilayered fabric façade. We found the addition of just a few millimeters of Aerosil to be the equivalent of 10cm of concrete,” explains Haase. “The second was to investigate values of translucency, which we found to be dependent on the thickness of the PCM materials and temperature (since PCMs change between liquid and solid phases).”

Another interesting set of projects from ILEK addressed the issue of openings in fabric structures. The first is the “Adaptive Multilayered Textile Building Envelopes” project (funded by The Federal Institute for Research on Building, Urban Affairs and Spatial Development, Germany), an example of which appeared at the 2010 Deubau Trade Fair in Essen, Germany. This project demonstrated a series of ideas for ventilation and window openings in membrane structures, using different coated elastic fabrics. The opening shapes include a 3-D iris (“Twister” by Elias Knubben), a membrane-clad kinematic frame (“Flow” by Torsten Klaus), and eyelike openings that are powered by pneumatic actuators (“Open Up” by Tomas Kratochvila).

The twister concept is being developed further. “In order for ideas like this to be accepted in the building trades, we have to develop the ideas and materials further,” says Haase, “to show energy efficiency and durability. It won’t be possible to convince anyone to adopt these solutions if the membranes need to be replaced every five years.”

“It’s quite difficult to create an elastic material for outdoor applications,” says Wagner. “None of the presently-available materials work well against snow and wind loads—you would have to add some sort of underlying supports for these conditions.”

“There are two key materials you can consider if you want to build a dynamic membrane structure without mechanical framing elements: PTFE or PVC-coated polyesters,” says Cremers. “These materials can have 20 years of performance, like other construction-grade materials. And even these materials must be designed and used properly. And this includes the processes of fabrication, transport and installation.”

In summary, one of the biggest challenges in designing dynamic structures is the availability of materials. As creative solutions emerge, so will the technology and materials: The development of lightweight, wide span roofs. Before many of the visionary works that have been created for smaller buildings can be realized, issues such as acoustics, transparency, energy efficiency and elasticity must be resolved to the satisfaction of authorities issuing construction approvals and customers considering the total cost of ownership of a structure.

Munich-based contributing editor Mark Zeh writes frequently about design and innovation.

Fabric Architecture | May 2012

By Mason Riddle

When the DR Koncerthuset (Copenhagen Concert Hall) opened in January 2009, it reconfirmed Jean Nouvel's powers as a visionary architect. The 26,000m² concert complex is 45m in height and encloses a series of volumes that include the main 1,800-seat concert hall and three smaller, more flexible performance spaces. It is the home of the Danish National Symphony Orchestra.

From the exterior, the cubelike DR Koncerthuset (DRK) is a compelling structure that changes under the light of day and night. Most notable is its cobalt blue skin, a Stamisol® FT 381 fabric by Serge Ferrari in a hue that would make Yves Klein weep. Named Ice Blue, the fabric has been stretched over a structure of steel beams, tension cables and a glass facade and functions as a translucent veil revealing the armature and spaces within.

A quality of mystery infuses the building, which has been lauded for its intimate performance spaces. By day, the outlines of the interior performance hall and studios, and people moving about on different levels can be seen through the blue skin. By night, the deep blue textile façade serves as a giant screen for projected video montages. “The façades are diaphanous filters permitting views of the city, the canal and neighboring architecture,” states Nouvel. “At night these façades become screens for projecting images.”

The DRK is a striking new landmark for Denmark’s capital, even more noteworthy because it is located in an undistinguished residential and commercial district being developed at the rim of the old inner city. Because of the nature of its transitional urban site, Nouvel first conceived of the blue screen as a kind of “magic lantern” that would attract other structures. “I tried to think about myself as an architect in the 11th century who had to build a cathedral in a city in Europe, and how the buildings then happened around the cathedral. This was possible because this is probably the largest and most public building here,” says Nouvel.

Nouvel’s design strategy was to create a dialogue with the unremarkable site and its bold design and the Ferrari fabric’s unique qualities allowed it to do so. It evokes a sense of restrained drama as the translucent blue textile merges the building’s interior and exterior worlds. By day, passersby can visually access the interior spaces, albeit opaquely, and by night local residents and visitors become an audience for the projected video montages.

The strong, durable blue skin imparts the DRK with a sense of lightness and luminosity. To create the skin, 16,000 m² of the fabric were stretched over panels measuring 5m by 15m to 15m by 15m. The membrane is 100% recyclable and has a warranty of 10 years.

Nouvel acknowledges that the DRK building with its lush auditorium and excellent acoustics is a homage to Hans Scharoun’s 1963 Berlin Philharmonie. Moreover, critics discuss it in the same sentence with Frank Gehry’s 2003 Walt Disney Concert Hall in Los Angeles, Calif., and Herzog & de Meuron’s still-under-construction Elbphilarmonie in Hamburg, Germany. (At a cost of £360 million the DRK is nearly twice as expensive as Gehry’s Walt Disney Concert Hall, which cost £190 million. The huge cost overruns resulted in the unpopular downsizing of DRK’s staff and orchestra posts.) Like the best of buildings, the DRK proves, with its bold Yves Klein blue face, that exceptional design and functional, intimate spaces are not mutually exclusive.

Contributing editor Mason Riddle writes frequently about design and art. Her piece on a rural New Zealand residential shade structure appeared in the Jan/Feb issue.

Fabric Architecture | May 2012

By Samuel J. Armijos

It has been 45 years since the German Pavilion was erected for Expo ’67 world’s fair in Montreal, Q.C., Canada. The structural system of this early fabric structure was a steel cable net that supported a pre-stressed textile membrane. The 7,200m² structure was open on all sides, with wind-deflecting glass walls on the ground floor and an operable skylight on top that would be open for natural ventilation in summer and closed with aprons against the roof membrane for heating in winter.

The purpose for using a fabric structure then was to create a low-cost roof with a translucent material that allowed natural daylight to filter in and would reduce the need for artificial lighting, heating and cooling.

Some things never change—or do they?

Today’s membranes are more durable and translucent than ever and some materials—like ETFE and insulated membranes with components such as aerogel—offer higher R values and additional benefits, but at what cost to the owner? Membranes come from all over the world and can have a life span of more than 30 years, yet the perception is that some materials are becoming so expensive that they are competing in price with traditional materials such as wood, glass and metal. However, the membrane may be the least of your cost.

When it comes to choosing the right “skin” for your building (new or re-cover), consider the structure’s other costs (steel, installation, access) and weigh the initial cost of all components against the operational, service and maintenance costs required on the roof over time. The biggest advantage fabric has over traditional materials is its translucency and its ability to reflect direct UV rays.

The solution to choosing the right skin is to balance the “needs” versus “wants” of your project and do your homework.

• When is your facility being used? Some facilities are used more often during the day and may not need as much artificial lighting.
• Where is your structure located? Structures in cooler climates tend to require more energy than structures in warmer climates.
• Are stainless steel cables necessary? In many cases PVC-jacketed galvanized cables, which are lower in cost, may be acceptable.
• What paint finish does the project need? Paint finishes vary from painted steel to powder coated steel to stainless. They all come with different initial cost or long-term servicing.

Choosing the membrane may be the most difficult decision to make because most people are unfamiliar with its performance as both building envelope and structure.

To insulate or not to insulate

There are a number of ways to insulate a fabric structure, including applying batt insulation to a liner, installing a single layer with a liner below it and blowing air between the layers or using state-of-the-art ETFE or insulated membranes.

“The primary issue with insulation of tensile membrane roofs is whether and how much light transmission is desired,” says David Campbell, PE, president of Geiger Engineers. “If daylighting through the assembly is not a design objective, tensile membrane roofs can be insulated with any conventional insulation in a ceiling assembly or liner.For example, the student center building at the University of LaVerne, California, is insulated with conventional fiberglass bat insulation. The assembly is opaque.

“Blowing air between an outer fabric layer and a liner does not constitute ‘insulation,’ ” says Campbell. “What it does is keep dry air at the underside of the outer fabric to reduce condensation.” One should also study the operational cost involved in blowing air between membranes. The blower does not need to be on all the time. However, it will increase net heat loss and therefore is less energy efficient than not blowing air at all.

Batt insulation is primarily used in frame supported membrane structures and not tensile structures and reduces, if not eliminates light transmission. This insulation also requires an additional step in the installation process.

ETFE, which is a film not a fabric, comes in translucency as high as 98%. As a cushion or foil, ETFE can come in two and three layers and offer R-values in the 2 to 4 range, but it requires a blower running 24/7 to be structurally stable. According to Campbell, “ETFE cushions are all well and good but air movement from convection and the makeup air in the cushion cells results in heat loss. The ETFE cushions have leakage that requires replacement no matter what the thermal goals might be.”

Tensotherm™ is a proprietary material created by Geiger Engineers, Birdair Inc. and Cabot Corp. and manufactured by combining Teflon®-coated fiberglass and aerogel. Aerogel is a synthetic, porous material derived from a gel in which the liquid component of the gel has been replaced with a gas. It provides thermal insulation with light transmission in a compact composite membrane panel installed in a single operation. The aerogel insulation medium is hydrophobic, maintains its thermal insulation value when compressed and does not deteriorate with age.

To insulate or not to insulate

Another perspective in the skins games comes from Richard Nelson, inventor of the Liquid Foam Insulation (LFI) technology, which uses bubbles in between layers of highly translucent fabric for a system he calls SolaRoof. According to Nelson, “The SolaRoof building technology provides full environmental control in all climates, especially temperate and northern locations, at a low cost.”

The SolaRoof is ideal for cold climates, efficiently collecting solar heat gain during the day and conserving this low temperature energy using the LFI overnight. In warm climates, the SolaRoof can prevent overheating by using the LFI to reduce heat gain and a water cooling process for temperature and humidity control within the SolaRoof building.

Nelson’s goal is not so much the use of insulated membranes for long-span structures but for sustainable and more humanitarian purposes. In collaboration with Life Synthesis and Phoenix Planning Design, Nelson has designed the AgriPOD, a greenhouse project suitable for both urban and rural use. It is particularly suitable for areas considered unusable for growing due to lack of water and good soil. The AgriPOD can be used on rooftops, car parks but also on ground or rocks. By using hydroponic and other revolutionary growing techniques, crops can be produced in places previously believed unsuitable.

“What makes this project different is that it aims to develop a revolutionary new solar bubble greenhouse that reduces the amount of water required and extends the growing season, thus increasing food production,” says Nelson. “Essentially, the benefits are that the system creates a totally controlled environment and allows food to be produced year round extending the growing season. This means having two, three or four crops a year depending on the situation and location. There are also added benefits such as reduction in the amount of water required and, if set up properly, purifying saltwater to enable it to be used in the food production process.”

Nelson is working with Norway’s Hydro Group to develop the AgriPOD project for the Rio + 20, the United Nations Conference on Sustainable Developments to be held in Rio de Janeiro, Brazil, in June. Prototypes have been made (6m by 9m) but the concept shows promise in sizes larger than 900m². The goal now is to make the system low in cost. Clear glass scrim/HDPE film laminate with an aluminum frame is currently used, and the cost and size of the bubble mechanical system is based on the size of the structure. The structure has recently gained interest from the equestrian market.

So how do you like your fabric structure?

A fabric structure is primarily made of three components: steel, cables and fabric. The structural system used can vary depending on collaboration between the owner and the design team (designer, engineer and fabricator). Some clients prefer a structure with more steel than tensile fabric. The steel and structural components of a tension fabric structure can be more than 50% of the overall cost. It is up to the designer to find the most efficient design based on the structure’s criteria and purpose.

The same could be said of the cables or edge treatment. Cables are associated with tension fabric structures and come with their own set of costs. End fittings and installation play a big role. By replacing catenary edges with clamping and straight edges, the price increases.

Finally, the owner or client’s representative needs to do homework on the membrane. Fabric structures can come in single layers, multilayers and insulated membranes. They all come with a cost beyond the cost of rolled goods. Although these types of membrane systems work for enclosed roofs, many fabric structures are “open air” structures and these systems present another issue: sound absorption and sound reflection.

Whatever materials are used, the addition of light-transmitting thermal insulation results in roughly 50% more cost than a structure with a single layer PTFE and a liner.

Samuel J. Armijos, AIA, is vice president of FabriTec Structures, a brand of USA Shade and Fabric Structures. He is author of Fabric Architecture: Creative Resources for Shade, Signage and Shelter.

Fabric Architecture | May 2012

As part of a campuswide redevelopment of Melbourne Girls’ Grammar School, the Wildfell middle school building seeks to create a rich learning environment for middle year children on a dense suburban site in South Yarra on the outskirts of Melbourne, Australia. Designed by Sally Draper Architects (SDA), the Wildfell forms the heart of a sophisticated school complex with a strong environmental sustainability program that integrates indoor and outdoor learning spaces.

Because the facility was designed during one of the country’s most devastating droughts, it is understandable that water and its conservation would be paramount in the client’s mandate for the new development. Responding to that mandate, SDA, working with Oasis Tension Structures (Australia) Pty Ltd, designed a lightweight tensioned fabric structure that provides shade and a sense of enclosure while simultaneously contributing to the sustainability goals.

The structure’s offset inverted fabric cone helps gather rainwater in its giant funnellike form and directs it to enormous reservoirs buried deep beneath the courtyard’s landscaped gardens, which is then used to water the plants to ensure survival. Water collected flows along the tensioned tie-down cables of the inverted cone into the reservoirs, producing a drumming sound on the fabric roof and a vortex of rushing water on the cables—a symphony of sight, sound and atmosphere on display during rainstorms.

To minimize impact on the delicate landscape, the fabric structure is supported by only two canted mast supports at one side of the rectangular canopy and the main building façade at the other side making the structure appear to float above the space. The crisscrossing tie-down cables of the inverted cone stiffen and stabilize the structural assembly and express the dynamic forces at play.

Fabric Architecture | May 2012

This restaurant overlooks beautiful Lake Garda in northern Italy, not far from Verona and the Swiss border. In recent years, the proprietor found demand for service such that the outdoor dining terrace needed to be pressed into use year round. To exploit the underused space, the restaurateur commissioned a shading structure to cover the terrace during the three seasons when colder weather prevailed.

BAT USA designed a motorized system that uses a single piece of fabric to cover the sliding segments of the aluminum frame system. The retractable aluminum extruded sections, sliding on fitted carriages that nest snuggly when fully retracted, are connected by stainless steel joints designed to resist any corrosion.

The structure is integrated with light and a sound system as well as glass side closures to make an attractive atmosphere for dining.

Fabric Architecture | May 2012

Ahti Westphal, a recent graduate in architecture from the University of Minnesota, has combined a number of personal interests with the design and construction of his luminous “Blue Cube” retreat located on Grindstone Island overlooking Rainy Lake that straddles the Minnesota-Ontario border. The hand-built structure on the Westphal family’s summer homestead is a testament to the designer’s interest in high-tech materials, their application in architecture and nature as inspiration.

“The Blue Cube is the first example of a woven polyvinylidene fluoride (PVDF) used for architectural application,” says Westphal. “The blue enclosure is a single layer of the highly nonreactive PVDF that is resistant to UV degradation, wide temperature extremes, chemicals and [when extruded] maintains a hard surface resistant to abrasion and wear.” Rainy Lake is located near International Falls, Minnesota, the “icebox of the nation,” with temperatures often ranging from minus 40F to 90F throughout the year, a true test of material durability. PVDF—or Kynar® from Arkema—shares similar low-friction properties with PTFE and ETFE that prevent dirt and other accumulates from sticking to it. Essentially it is self-cleaning.

Westphal took a large sheet of the woven PVDF and fitted it by friction mounts to a painted carbon steel frame that wraps all four sides of the structure. “I think of it as a tightly stretched curtain,” he says, that counteracts the wind and keeps out insects—no small accomplishment for that part of the world. The fabric is 100% recyclable and has a lower melting point than woven metal meshes, making it, in Westphal’s estimation, a highly sustainable building material. He plans to continue experimenting with it and testing it in other architectural settings.

FabricArchitectureMag.com | April 16, 2012

Textile Roofs 2012
May 14–16
Berlin, Germany
University of Technology Berlin

Textile Roofs 2012 workshop provides fundamental information, state-of-the-art textile roof engineering and practical, hands-on sessions. Lectures—presented in English—are given by leaders in the membrane structure industry.

During afternoons, workshop sessions will provide opportunities for both physical and computational modeling under the guidance of the instructors. Each participant will work with advanced and high-end software. In parallel sessions, participants will learn about a joint project on the roofing of one of the Geodätenstand platforms. Results of this joint project with students will be presented at the last day wrap-up.

Workshop highlights

Monday, May 14, evening: special guest lecture by Wolfgang Rudorf-Witrin, of CENO Tec GmbH, Greven, Germany.
Tuesday, May 15, evening: sightseeing tour of Berlin by boat, followed by a banquet.

Invited speakers include:

• Ms. Prof. Birgitt Brinkmann, Leuphana University Lüneburg, Germany
• Olivier Dufour, Esmery Caron, Dreux, France
• Françoise Fournier, Serge Ferrari SA, La Tour-du-Pin, France
• Prof. Christoph Gengnagel, UdK Berlin, Germany
• Prof. Dr.-Ing. Dr. h.c. Lothar Gründig, University of Technology Berlin, Germany
• Dipl.-Ing. Matthias Gühne, Textilbau GmbH, Trittau, Germany
• Dipl.-Ing. Kai Heinlein, Karlsruhe Institute of Technology, Germany
• Jürgen Hennicke, University Stuttgart & TU Vienna; Stuttgart, Germany/Vienna, Austria
• Dipl.-Ing. Jürgen Holl, technet GmbH, Stuttgart, Germany
• Rogier Houtman, Tentech BV, The Netherlands
• Dipl.-Ing. Christoph Paech, schlaich bergermann und partner, Stuttgart, Germany
• Wolfgang Rudorf-Witrin, CENO Tec GmbH, Greven, Germany
• Dr.-Ing. Dieter Ströbel, technet GmbH, Stuttgart, Germany
• Osama Thawadi, Gulf Shade, Bahrain
• Dipl.-Ing. Jürgen Wacker, Wacker Ingenieure, Birkenfeld, Germany
• Prof. Dr.-Ing. Rosemarie Wagner, Karlsruhe Institute of Technology, Germany
• Dl Dr. techn. Robert Wehdorn-Roithmayr, Formfinder Software GmbH, Vienna, Austria

Cost: €800 until May 1, 2012; €850 after May 1.

A detailed program and registration can be found here. Or obtain more information by emailing mail@textile-roofs.com

This June, a fairy tale is set to unfold when the European football championships begin in Kiev, Ukraine, with a lovingly renovated stadium where the final games of the Euro 2012 will be played.

Eighty-nine years ago, in the same city on the same grounds, the “Red Stadium” was built on the site of Alekseevsky Park for the second All-Ukrainian Olympic Games in 1923. Over the decades, the stadium was rebuilt and renamed several times. Now called the Olimpijski National Sports Complex, the sports venue has been completely renovated for the Euro 2012. Work was carried out from December 2008 to October 2011. With their renovation plan for the stadium, gmp Architects respected the historic nature of the construction which holds 68,000 spectators: they positioned the supports for the new roof construction outside of the existing distinctive upper-tier stand made of reinforced concrete.

Engineers, Schlaich Bergermann und Partner designed the 45,000m² translucent membrane roof that features 640 high points of light ETFE foil domes. The roof support structure is a spoked-wheel construction with two outer pressure rings and a pull ring on the pitch side. A sophisticated design of interlocking cable trusses span over the seating area to support PTFE-coated glass fiber fabric panels in 80 radiating bays. Each membrane bay is undulated by eight high points suspended by cables.

The order of assembly involving the cable-support structure and the membrane, as well as the cutting pattern design of the membrane roof, was entrusted to engineering consultants formTL. After examining various options for installing the cable-support structure, formTL’s final concept involved pre-assembling the ring cables, radial cables, and knots on the ground, then lifting them up to the upper pressure ring and finally pre-tensioning the lower radial cables. The upper radial cables had to be pulled up equally to the upper pressure ring on all 80 axes in order to avoid overstress in the cable-support structure.

Three qualifying games, a quarter final and the final of the Euro 2012 will all be played at the Olimpijski Stadium. The sports venue is fitted with a roof that will provide fans with light, shade and protection against the rain, all set to witness unforgettable football highlights in all weather conditions.

The annual “Call for IFAI board candidates” from the Industrial Fabrics Association International was sent to the association’s voting membership on Monday, April 9. Applications are due May 28, 2012.

In June, the IFAI board’s Leadership Development Committee meets to consider the qualifications of the candidates. In July, the association’s membership is notified of committee’s recommendations.

Election results are announced at the 2012 IFAI Expo Americas, Nov. 7–9 in Boston.

IFAI members are encouraged to recommend candidates for the board:

Cherie M. Schmit
Executive Assistant to the President
Industrial Fabrics Association International
1801 County Road B. West
Roseville, Minnesota 55113
U.S.A.
Ph: +1 651 225 6985
Fax: +1 651 225 6977

The Solar Sail—with integrated LED RGB lighting—brings art and science together to promote clean energy for electric cars in the Austin, Texas nearby community of Pflugerville. The Solar Sail charging station has been installed by Pvilion as a demonstration to the green energy savvy Pflugerville community, which soon will become home to the largest solar panel array in the United States as a beneficiary of major investments in solar-generated technologies by local and national businesses and the Department of Energy. The Solar Sail charging station is located at the entrance to Pflugerville’s new Renewable Energy Park.

Solar Sail is a turn-key product from tensile-PV startup Pvilion that offers ready, out-of-the-truck “one wire in/one wire out” easy installation. It has been engineered by licensed professionals to meet permanent building code wind and snow loads.

The charging station will be unveiled on April 5, 2012 at an event sponsored by Pvilion and the Pflugerville Community Development Corp., in partnership with the Austin Chamber of Commerce.

Source: Pvilion

Located on the north lawn of the United Nations campus, New York City, the U.N. Interim Canopy is a porte cochere structure that sits adjacent to the U.N.’s new temporary General Assembly building, designed by HLW International. The structure serves as an entrance pavilion and security screen for general assembly delegates. The structure is envisioned as a relocatable building to be moved to another part of the campus at the completion of the five-year renovation.

The renovation of the historic U.N. buildings is scheduled as a five-year project. Due to the temporary nature of the interim buildings, the environmental impact and sustainability of the porte cochere was of prime interest to the U.N. and was considered at the outset of the design process. Realizing these concerns, the design team introduced the concept of relocate-ability. Why recycle parts when you can recycle an entire structure? The porte cochere may be relocated to another location on the U.N. campus or to any other site of the U.N.’s choosing. The final design has minimal anchorage points and is modular using prefabricated steel trusses that allow quick installation that minimizes the impact of construction crews on site. The high-tech textile membrane’s function is two-fold: it provides support as a working tensile element equally distributing structural loads, and it defuses sunlight to naturally illuminate the spaces below.

The client required visual privacy for the U.N. delegates and ventilation for idling cars under the structure. The structure uses two fabrics, a Teflon-coated glass fabric as the main fabric and a silicone-coated glass fabric for greater translucency in the arches. Functionally, the canopy provides shelter for the motorcades as they load and unload delegates and requires ventilation for the idling cars inside. The open façades and linear vents that run the entire length of the trusses allow fresh air to flow freely throughout the enclosure. In addition to the Venturi effect natural ventilation [the natural increase in wind speed due to air passing over vertical surfaces], exhaust fans are mounted in the trusses to remove fumes as required.

The client and its security teams, including the Secret Service, were very satisfied by the project because it provides the necessary visual privacy, passive and active ventilation and a sustainable approach to the project by using a design that can be relocated to other parts of the U.N. campus. The client called the structure a “functional work of art.” The porte cochere offers an elegant counterpoint to the rectilinear architectural elements which inhabit the site. This temporary addition to the historical site is at once a suggestion of ideas that speak not only of the present, but look forward to future possibilities of the United Nations, its mission and what humanity may achieve.

The project won an Outstanding Achievement Award in the IFAI 2011 International Achievement Awards program.

The Museum of Modern Art (MoMA) and the MoMA PS1 Brooklyn-based gallery announced that HWKN (HollwichKushner) was the winner of the 13th annual program that offers emerging architectural talent the opportunity to design and present innovative projects, challenging each year’s winner to develop creative design for a temporary, outdoor installation at MoMA PS1. Requirements demand that the designs provide shade, seating and water, and address issues of environment, including sustainability and recycling.

The winning project, “Wendy” by Matthias Hollwich and Marc Kushner, is composed of nylon fabric treated with a ground breaking titania nanoparticle spray to neutralize airborne pollutants. It is expected that during the summer of 2012, “Wendy” will clean the air to an equivalent of taking 260 cars off the local roads. By combining off-the-shelf materials and scaffolding systems with the latest in nanotechnology, the HWKN project is able to produce both and out-of-the-box ecological statement and a bold architectural gesture.

A previously posted Fabric Architecture magazine article contains information about TiO2 applications.

Source: MoMA

Northland Stadium, Wangharei, New Zealand

FabricArchitectureMag.com | January 19, 2012

The project brief: to design and build a stadium in the Northland city of Whangarei, New Zealand, with a seating capacity of more than 3,000, the majority under cover. In addition, the client required corporate boxes and hospitality areas sheltered from the elements.

The project purpose: to create a stadium that could be used for sporting and concert events as part of a major redevelopment of Okara Park in Whangarei that would introduce significant sports activity in the area via a regional events center incorporating new grandstands and terraces to accommodate up to 25,000 people.

A tension membrane roof was a cost-effective solution for covering the stadium because it could be fabricated and installed more quickly than traditional construction methods and materials. Additionally, fabric offered beautiful aesthetics and high translucency.

Built under a tight time frame and budget, the stadium uses a concrete frame substructure topped by a cantilevered lightweight steel superstructure that is unobtrusive to the spectators. The 100 meter-long building is slightly curved to maximize the angle of spectator view, emphasizing the natural amphitheater of Okara Park, making the seating surprisingly intimate and in close proximity to the playing field.

The Northland Stadium has been a success and is in regular use since its 2010 debut. Moreover, it was the only stadium that participated in the 2011 Rugby World Cup with a PVC tension membrane roof.

Source: Structurflex

Fabric Architecture | January 2012

The largest tethered airship ever made created the world’s largest projection surface and became the centerpiece for one of the greatest shows on earth, watched by millions of people worldwide. The XIX Commonwealth Games were held in Delhi, India, October 3–14, 2010, and included a total of 6,081 athletes from 71 Commonwealth nations and dependencies competing in 21 sports and 272 events. Opening and closing ceremonies were held at the Jawaharlal Nehru Stadium, highlighted by the massive floating structure. U.K.-based Lindstrand Technologies was approached about the feasibility of creating a helium-filled structure to float above the stadium, create a lifting body for displays and scenery, carry lighting equipment and provide a huge projection surface. The resulting one-of-a-kind Delhi Aerostat, designed by Lindstrand Technologies’ Lee Barnfield, was a 22,000m³ helium-filled structure that measures 80m long, 40m wide and 12m high.

The huge dimensions of the aerostat meant that it couldn’t be shipped to India in a single piece. The main body was split in four sections and assembled on site in Delhi. The time between the final events in the stadium and the closing ceremony was 36 hours, allowing Lindstrand just 12 hours to reinstall the aerostat—a phenomenal feat for a structure of that size. The total aerostat structure uses nearly 10,000m² of Ferrari Précontraint® 402 fabric, plus approximately 5km of electrical cables to operate the various fans and valves required to maintain pressure. The Delhi Aerostat received a 2011 Award of Excellence in IFAI’s annual International Achievement Awards competition.

Further developments to the Nov/Dec issue news about the London 2012 Olympics inform us that Dow is working with Cooley’s Commercial Graphics and Engineering Membranes divisions to develop and manufacture a sustainable fabric that will be used to wrap London’s iconic Olympic Stadium for the 2012 Olympic Games. Dow is also working with Rainier Industries to print and fabricate the graphics wrap; installation will be by Shade Worldwide.

Fabric Architecture will post regular updates in future issues on this exciting project.

A floating fabric sculpture graces the entrance atrium in the new MediaCityUK Living Lab at the University of Salford (Manchester, England). Appearing to hover above students throughout the entryway, the ribbon-like sculpture interlaces itself through the space and up to the second level atrium ceiling stretching nearly 22m from end to end.

Designed, engineered and installed by Fabric Architecture Ltd., Gloucester, the bespoke “Ribbon” uses a patented internal tensioned structure framing system, ArchiClad, in three discrete, but connected sections in a rotating form made up of 23 frames, each wrapped in fabric.