FabricArchitectureMag.com | January 19, 2010

Reviewed by Aaron Westre

TensileDraw is a new 3-D membrane modeling tool provided by Mehler Texnologies. Mehler is a German company specializing in the production of a variety of coated fabrics for architecture, transportation, sporting and other industries. The software was developed for Mehler by M E+C S.r.l., an Italian company that produces a variety of analysis and form-finding applications for engineering and architecture. TensileDraw is available as a plug-in for either AutoCad® or Rhino. Both are available as free, feature-limited (LT) or full-featured, pay versions. The Rhino LT version is reviewed here.

As with most membrane design software, the designing with TensileDraw follows a step-by-step sequence from defining initial boundary geometry through form-finding. The Rhino version of the plug-in is operated via an installed toolbar or a series of commands. The integrated tutorial window is useful for getting accustomed to the software and a PDF manual also is available. The design sequence starts with configuring “styles” that define the properties of the membrane, borders and cables that will be used in the structure. An initial mesh is then created by selecting a border shape in the Rhino modeling window. Border shapes are drawn directly in the modeling window and any closed polyline can be chosen as a border. An initial mesh is created after parameters such as border style, warp/weft offsets and center point are specified. Radial or rectangular meshes can be created. The resulting mesh can be manipulated like any other geometry in Rhino, such as moving specific points to new locations according to design requirements. Once the mesh is manipulated so its anchor points are in their correct positions, these points are fixed in place. Form-finding calculations then shape the membrane according to the material parameters and forces defined by the user. When a suitable form is found a single command creates the surface planes of the membrane in Rhino.

The form-finding process can be repeated as many times as necessary in TensileDraw. Anchor points can be moved at any point and the calculations re-run to see the results. Quick iterative cycles are easily achieved since the initial setup steps are bypassed. Final designs can be further analyzed by having TensileDraw generate a report with measurements, stresses and tensioning requirements.

TensileDraw has a few limitations that may lessen its suitability for some purposes. The LT version lacks features such as defining boundary joints and more advanced reporting and curvature analysis. It also limits the number of nodes in a structure to 400, which reduces the accuracy of the membrane surface modeled. The full version of the software addresses these limitations, but is quite expensive at 3,500 euro.

One of the primary advantages of TensileDraw over stand-alone applications is the ability to work with the created geometry directly in the Rhino modeling environment. This eliminates the need to export geometry for further manipulation or rendering in another application. For instance, using the Rhino’s built-in curvature analysis tools, designers can get rapid feedback on potential problem spots in their designs. Rhino also offers several fabrication-oriented tools that can dovetail nicely with designs created in TensileDraw.

Overall, TensileDraw offers the advantages of rapid form-finding, easy iteration and full integration with familiar modeling tools. Installing the free version is recommended for designers looking for an integrated solution.

The free LT version of TensileDraw can be downloaded at www.mehler-texnologies.com/EN/software.php?pid=37. The full version of the software is available for purchase at www.me-c.it/.

Aaron Westre is the founder of Artificial Natures, a research and development firm that creates software tools for architectural design.

God is in the details when it comes to tension structure design

Fabric Architecture | January 2010

Ludwig Mies van der Rohe got it right when he said “God is in the details.” Another well-worn phrase has it that we must sweat the details and the big things will take care of themselves, so with this article we look at tension structure connection details that have proven reliable over time.

The connections are where all the forces that act on and within a tension structure come together, and where the success of the design is made or lost. Problems that occur in a tension structure are most frequently found at the interface between different systems. Tension fabric structures can be described as a convergence of three such systems: a fabric membrane, the supporting structure that anchors and supports the membrane and the tensioned cables that tie the membrane system to the supporting structure. Within each of these three systems is a number of important, crucial connections.

The key to good design practice with tensile structures is to establish appropriate criteria for the connection assemblies. Keep in mind the following interrelated criteria throughout this paper:

• Performance: function, safety and structural behavior
• Constructability
• Cost
• Aesthetics

Performance

A strong performance focus is critical to good connection design. Special functional requirements must be carefully articulated:

• Will the connection be subject to extensive movement, out-of-plane movement, vibration, or repeated assembly and disassembly as a temporary structure might be?
• Will the connection be exposed to an extreme environment: extreme hot or cold, a marine environment, high humidity or high industrial pollution levels?
• What amount of rotational freedom is required between joined parts?

Safety issues are largely a function of satisfying code requirements and using appropriate engineering methodologies in a structure’s design. Design load requirements and safety factors must be carefully assessed with respect to the structure’s application.

Sophisticated fabric tension structures are being used with increasing frequency as permanent architectural structures, often in public buildings. Higher magnitude loads often require a complete reworking of familiar connection details that are used in temporary installations. Engineering analysis by a competent firm experienced in tension fabric structure engineering practices provides the loads and stresses that the structure’s connections must be designed to accommodate. Comprehensive engineering analysis is a prerequisite for good connection design. Maintenance is an oft-neglected performance criterion that potentially affects safety, cost and aesthetics. Requirements for maintenance are determined as a direct function of three key issues of connection design: processes, materials and finishes. These will be discussed later in the paper.

Constructability

Constructability (the means and methods of fabrication, assembly and erection) is certainly an important design aspect that can affect cost and quality. We’ve all heard about the wonderful designs that cannot be built. Moreover, a primary objective of good connection design is predictable quality, schedule and cost regarding the fabrication and installation of the connecting components and assemblies. Designs developed without rigorous evaluation of their fabrication and installation requirements will likely result in unanticipated fabrication and assembly problems that can easily affect cost. Good design practice embodies in its product the spectrum of considerations spanning the building process, from concept design through fabrication, assembly, erection and life cycle maintenance.

Cost

Cost is usually regarded as an important consideration, and is often the predominant design driver. Connection assemblies for fabric structures typically represent a significant cost center, particularly in permanent architectural applications, which tend to be hardware-intensive (as opposed to software, i.e., the fabric membrane.) A strong focus on connection design will both reduce and control costs, contributing to maintaining the project’s budget.

Aesthetics

Aesthetics becomes a paramount design concern in many architectural applications of fabric structures. Connection detailing represents a prime opportunity for designers to add visual interest and excitement to a fabric design, but aesthetic considerations must start with a rigorous analysis of performance requirements and end with craftsmanship. Much can be done simply with good craftsmanship, but craftsmanship alone will not save a flawed design.

Understand the way in which the forces are moving through the connected components. Tensioned fabric structures are stable due to their doubly curved forms generated by tensile force equilibrium. Therefore, elements and connections must encourage and follow direct load paths. The displacements of tensioned structures produced by external loads are relatively large compared to those of more conventional construction systems. This quality must be kept in mind throughout all stages of tension structure design. Connections should allow for displacement and rotation. Details should be simple, flexible and in scale with the overall structure and material used.

Overall, be certain that you truly understand what your connection design will look like when built. Computer renderings are helpful, but full-scale mock-ups are by far the best format for determining issues of form and proportion, as well as fit and function. Spend as much time as you can afford looking at other fabric structures, drawings and photographs of built connection details, keeping in mind what works visually and what does not. Do this, and you should soon recognize tension structure connections that work well both functionally and visually.

Careful attention to joinery and geometry brings a work of art (and a functional pedestrian bridge) to a busy intersection in Colombia

Fabric Architecture | January 2010

This unusual fabric and bamboo structure has several sustainable design advantages going for it, starting with the design of the intersection it crosses. The intersection is a mini cloverleaf with clear and practical separation of auto and pedestrian circulation systems. A modified “roundabout”—a traffic control concept known to reduce pollution and gas consumption by avoiding stoplights and idling engines—it is located at a major crossroads in the city of Cúcuta, near Colombia’s northeastern border with Venezuela. To minimize gasoline use, the exit and entrance ramps from two directions rise only 3.5m above the pedestrian grade (or “zero-level”) while the main four-lane thoroughfare descends 3.5m to make a total of 7m difference between the lowest and the highest roadbeds. In a subtle nod to the concept, the steep slopes leading down to the lowest road level are planted with an anti-erosion ground cover of clover.

Like a handcrafted wooden puzzle, the bridge relies on each piece of bamboo to contribute to the integrity of the structure. Two broad arches, one each side of the pedestrian deck and each composed of a trio of large-diameter bamboo, carry the weight of the bridge and rest on major foundations set into the embankments. Three is the favored number, as bundles of three medium-diameter bamboo support the deck transversely at regular intervals, while a secondary arch of shallower curvature undergirds the deck assembly. Bamboo struts point diagonally up above the two bridge ends to provide cross bracing and structural support for the tensioned saddle-shaped fabric cover.

“Working with bamboo is a pleasure,” says Jörg Stamm, a German-born carpenter who did the bamboo construction, “as it is already a finished product and it feels good in your hands: no splinters, no roughness and it is very light.” Bamboo is an ideal construction material for a number of reasons. Unlike metal, with bamboo there is no mining of raw material, no melting of ore, no anti-corrosive paint required to protect it and thus has a relatively low carbon footprint. Structurally, bamboo is a tube with mechanical properties similar to light steel. As for Life Cycle Assessment (LCA), according to Dr. Jules Janssen of Eindhoven University of Technology, bamboo has an LCA 50 times lower than steel and three times lower than dimensional lumber for equivalent strengths.

For the protective fabric roof, Castro Rojas Ingenieros y Arquitectos Ltda., Bogotá, Cmarca, Colombia, designed a gently curved saddle form with outrigger steel cable tie-downs at each corner securing the roof to the embankments as well as contributing to the overall structural stability of the bamboo.

As far as anyone knows, this is the first time that a tensioned fabric roof of this size has been combined with an all-bamboo structure of such magnitude. The refined connection details and craftsmanship prove that the bridge in Cúcuta is more than a pedestrian structure, it is a work of art that has become a much-loved landmark for the community. The project won an Award of Excellence for projects less than 558m2 in the 2009 International Achievement Awards sponsored by the Industrial Fabrics Association International.

By Bruce Wright, editor of Fabric Architecture magazine.

Experienced professionals comment on how much it costs to build fabric structures

Fabric Architecture | January 2010

By Samuel J. Armijos

The hardest part of designing and building a fabric structure is determining its cost. There are three major components to a fabric structure—steel, fabric and cables—and every decision made about the design and its installation affects the cost. In general, the more complex and the more steel there is on a project, the more it will cost to design, fabricate and install. Also critical is what you see and don’t see. The fabric and hardware chosen are just as important as the paint finish and the foundations. Location, site access and labor rates also play a major role. Finally, there are different ways to proceed: design/build or plans and specifications. Confused? Want advice? Ask people with experience in tensioned fabric structures.

Design and engineering

Fabric structures are mostly used as a cost-effective solution for providing shade and shelter. The added bonus is that fabric structures are festive in nature and can be used for temporary or permanent applications. The beauty and cost of these structures is in the details. A designer’s signature style is often expressed in the details of a project.ÊDetailing fabric structures is no different.ÊArchitects, designers, consulting engineers and clients all have different ideas about how a fabric structure and its details should look, but may not know their subsequent cost. Consulting with a design professional can save thousands of dollars. Decisions can be made at the outset of the project to determine if it makes sense to do the project as a negotiated design/build or as a formal public bid. One way requires a set of construction documents to be prepared before a public bid while another can go out to specialized contractors as a performance specification or with schematic drawings.

According to Nic Goldsmith, senior principal at FTL Design Engineering Studio, New York City, the costs of design and engineering tensile structures have remained relatively flat over the past few years, even though construction costs have increased. What is seen, however, is a trend in the industry from a more traditional scope of professional services to a leaner “design engineering package” that can then be bid by specialized consultants as a design/build scope. This allows the owner to lock in construction numbers early and still create an even playing field for bidders.

Steel

Steel plays a major role in cost. Selecting the method by which primary components are made can greatly influence the overall cost of a structure. A minimum number of elements is usually desirable. A mast-supported structure is more cost effective than a frame-supported structure. Less is more. Be aware that the cost of designing custom components, such as tapered masts and custom trusses, needs to be weighed against the use of standard products (i.e., tube, pipe, etc.). The price of steel has been volatile over the past few years, and the time frame involved from conception to build out can play havoc on a project’s steel budget. The different material properties (strength, thickness, elasticity, weight, etc.) make material selection critical. For example, using high tensile materials with smaller cross sections most often implies higher material cost. However, using low strength materials with larger cross sections increases the weight and cost of the installation. A need for components to be highly abrasion-resistant, low maintenance and “vandal proof” also influences the choice of suitable materials. An important design factor often overlooked is the utilization of more common (commercially available) sizes and wall thicknesses. This is a large variable because it reduces drawings and fabrication costs, but sometimes affects the architects’ aesthetic intention. According to Jim Land, president of Affiliated Metal Industries Inc. of Cleveland, Ohio, a custom steel fabricator of tension fabric structures, the price of a ton of fabricated steel had gone up 50–60% in the past 10 years. In 2000 it was $2,200 per ton, and by mid 2008 it was $3,500 per ton and rising until the current economic crash. Closing in on 2010, it is currently around $1,900 per ton, but some projects are going for $1,500 per ton and less. With the current economic crisis, material prices are going down rapidly and fabricators around the country appear to be “buying jobs” left and right just to fill capacity through the winter months. But the buyer had better beware. Just because XYZ fabricating company spits out a lowball price today does not mean it will not come back for huge change orders or, worse yet, be unable to fulfill the contract obligations once the economy picks up.

Beyond the price and type of the material, a number of other factors can affect the price to contractors. Project timing, completeness of design, finish coatings, project scope, market price and commonality of materials used all have a major impact on how a project gets quoted out.

“The best advice I can give is to get a fabricator involved early in the design process. We can study the project’s design and constructability, suggest modifications and put real-world dollar figures into the costing at an early stage, allowing the project owner to change course earlier if needed,” Land suggests.

Fabric

Membranes have different costs as well. Some membranes have longer life spans than others and selecting a membrane should be based on application and lifespan. Membranes come with different top coats that provide different forms of protection. All membranes are not created equal.

“The cost of chemical feedstock used in the production of architectural fabrics has doubled this decade,” says Brad Hochberger, western regional sales manager for Seaman Corp., Wooster, Ohio, a manufacturer of vinyl-coated polyester. “Some of these increases have made it to the owners, but not all. Overall, the demand for architectural fabric structures has been robust, with many owners tending to prefer the higher end materials.”

Architectural fabric performance has improved with new long-lasting top finishes extending the life and cleanability of the membrane. Membranes are available with various options and costs to meet an assortment of needs and applications. It is worth researching the source and type of membrane and a fabric company’s history and warranty. To assure proper performance and long life of these structures, quality performance criteria must be established and specified by the architect, engineer or procurement agency. Read the fine print and ask for samples. Some fabrics require additional prep work and cost in order to be joined, while others may be hard to handle in the field. For membranes, symmetry and optimization of cutting patterns is important. The fewer the number of cutting patterns, the more cost effective the production.

Cables

Clients should be made aware of the difference not only of the quality but the price between custom parts such as cast and stainless steel fittings versus standard and galvanized parts (bolts, nuts, shackles, etc.).

According to Peter Katcha of Ronstan International, Portsmouth, Rhode Island, makers of architectural stainless steel fittings, “With the lengthening of product life cycle and durability of architectural fabrics, more of our clients are requesting stainless steel cable systems instead of galvanized. Stainless steel cable systems and hardware will equal and surpass the fabric’s life span. Galvanized cables will typically not meet the fabric’s life expectancy and can be the first material requiring replacement on the structure. Galvanized cables will lower the initial installation cost, but will increase the cost over time to maintain the structure.” There is common practice in the industry to mix galvanized cables and stainless steel fittings but make note: pay now, pay later or have a plan. Galvanized cables are much cheaper than stainless but over the last two years, stainless has dropped 10% in price, making it a worthy investment.

Install

Installation (which includes shipping and equipment) is the hardest part in cost estimating a fabric structure. Equipment rates and availability can change dramatically, access can play a big role in the install and shipping rates change as trucking costs and gas go up. As in real estate, tension structure installers play close attention to location, location, location. A project’s location can have a dramatic effect on cost. Projects requiring union wages can increase the price. Working in major cities where crane access and street closure permits are required will definitely raise the price of a project. The ability to transport components to the job site must be considered as well. Many times, projects require “multiple mobilizations” because the membrane cannot be installed right after the steel has been placed. The best way to check the pricing is to make sure your contractor has a “Means and Method” statement in their proposal or a written procedure on how they intend to erect their structure. A construction schedule for all to see prior to proceeding is highly desirable.

Anatomy of a fabric structure

The best way to understand the cost of a fabric structure is to request a Schedule of Value (SOV), or a breakdown of the major cost (design/engineering/project management; steel, fabric and hardware fabrication; installation and equipment and shipping.) The percentage of the overall cost can vary significantly depending on the complexity of the design, the material chosen, the location and access of the site, the cost of labor and equipment and the amount of material needed to be shipped. Keep in mind, fabric structures are normally priced by surface area because of their unique shapes.

Here is a basic rule of thumb:

Plan Area (Length x Width) X Shape Factor (H) = Surface Area

Shape Factor is a number that varies depending on the form chosen and is used to estimate the amount of fabric, including waste, used on a project. Mast-supported structures tend to have twice as much material as a hypar or a barrel vault design. Today’s computer programs can also provide surface area easily.

Surface Area X Cost per SqFt = Budget

The budget does not include foundations but it will give some idea on how much the fabric structure is going to cost. There is a large variable in cost-per-square-foot because the more steel used on a structure (frame-supported vs mast-supported), the more expensive it will be. Also, there are many grades of PTFE, PVC and HDPE. The key to building a cost-effective fabric structure is to design the lightest structure possible. Remember, less is more; light is even better.

Samuel J. Armijos, AIA, is architect and 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. He resides in Fairfield, NJ.

Fabric Architecture | January 2010

By Mason Riddle

Small projects

Not everyone gets a bird’s-eye view of his or her handiwork. But that is exactly what Sollertia Inc., Montreal, Canada, founder and president Claude Le Bel did when he leapt from an airplane above Parachutisme Nouvel-Air. Soaring above the fields and meadows, La Bel liked what he saw—a graceful, highly visible, tensile fabric canopy that easily identified the school’s rural location for parachutists. “I can testify firsthand that you can see the structure very well from the sky,” says Le Bel. “It does what it is supposed to do—tell the parachutist where is his home.” For Nouvel-Air, Canada’s leading skydiving school located in Farnham some 40 minutes drive from Montreal, Sollertia’s team of architects, designers and engineers was a perfect match.

Nouvel-Air’s owner, Michel Lamay, long on enthusiasm and short on cash, wanted the tensile structure to span a new bilevel, wood terrace with four goals in mind: create maximum shading for jumpers and visitors; provide maximum views to the sky; create a visual discourse between the canopy and the school’s architecture; and be “cheap.” The first three functional and aesthetic requirements were achieved easily enough through the design of three sail-like forms made from a micro-perforated PVC fabric (Naizil SunControl 410 white). Supported by galvanized metal masts installed in concrete footings at the terrace’s edge, these membranes all connect to the tallest mast that punctures the terrace at an angle, creating a visual path to the building’s entrance. The three sails work collectively to provide needed shade, a luminous degree of transparency and open vistas to the sky. Like a distant cousin, the project’s lyrical design makes a visual connection to the airborne parachutes.

Budget was another matter. “We needed to make the project as cost effective as possible and still have a great look,” states Le Bel. The answer? Use galvanized “off the shelf” metal poles instead of stainless steel for the masts. Nouvel-Air provided another notable cost-saver. From Sollertia’s drawings, Lamay and staff cut and fabricated the three sails themselves. “At first we were skeptical,” says Le Bel. “But the owner, being in the business of fabricating and repairing parachutes, knew what he was doing and it worked beautifully.” With this in-house labor perk, the project, which was begun in 2006 and installed in 2007, was completed for an enviable $50 per square foot.

Although galvanized poles were substituted for stainless due to cost, the PVC fabric was chosen because of its meshlike quality and that it would be sustainable for a much longer time than a less expensive fabric. Le Bel estimates the average percentages of total budget for the small custom Nouvel-Air project, as the following. Design and engineering 20%, fabric 23%, structure and hardware 30%, foundations 15% and installation 12%. Thus, the cost for the project design, foundations and the fabric was approximately 60% of the total Parachutisme Nouvel-Air project budget.

By the way, Sollertia is a Latin word meaning “ingenuity.”

Medium projects

SkySong, the signature design element in the Arizona State University (ASU) Scottsdale Center for New Technology and Innovation, embodies its name. In this new, partially completed mixed-use 17-hectare development, SkySong is an enormous custom tensile fabric structure whose swooping form suggests some futuristic amusement park ride. When the project is completed, SkySong will straddle the intersection of two connecting roads and connect four separate buildings, designed by Pei Cobb Freed. Two of the buildings are now occupied. In conjunction with Higgins Development Partners of Chicago, FTL Design Engineering Studio, New York City, designed the dramatic white structure and FabriTec Structures, Costa Mesa, Ca., supplied the fabric and constructed it. Tenants will have access to ASU resources.

According to Nic Goldsmith, FAIA, senior principal of FTL, the goal was to create a new urban icon for the ASU Scottsdale campus that would also be a shaded gathering space for students, faculty and workers. Visually and structurally complex, Skysong’s 4500m2 of Teflon®-coated (PTFE) fiberglass fabric (Sheerfil® I by Saint-Gobain) covers eight integrated conical-shaped structures, each of which is supported by a steel “leg”® measuring 34m in length and weighing 10,800kg. When completed, the undulating structure will be illuminated by white lights (Bega metal halide fixtures) and colored LED (Martin) fixtures that will allow it to change color for a specific need or event.

“In spite of its size, the interior space is surprisingly intimate,” comments Goldsmith. He likens SkySong’s rhythmic form to the configuration of the dancers in Matisse’s famous painting “The Dance” (1910), who move in rotational symmetry. “When you stand under it you have the sense that the forms are moving around you in rotational symmetry—it is not static at all,” explains Goldsmith.

A few budgetary concessions were made from the original concept. The steel column bases were initially to be conical in shape but are now cylinders. Also to reduce cost, the details and fittings below 6m are stainless steel and above are galvanized. “Above 6m these details are less noticeable,” says Goldsmith.

In Scottsdale’s intense solar climate, choosing the optimum fabric was critical. Although more expensive, the PTFE fabric has a shelf life of about 30 years. The benefit of replacing the fabric less frequently outweighed concerns of cost. Also, the LEED silver project is a passive solar structure that reflects light and heat. Of the approximate $230 million total project budget the infrastructure and tensile structure cost approximately $4-5 million. “It’s gotten tremendous response,” adds Goldsmith. “The mayor even likes it.”

Large projects

For the new 45,000-seat Nelson Mandela Bay Stadium in Port Elizabeth, South Africa, the critical environmental issue was not the sun, but wind. Known as the Windy City, Port Elizabeth is perched on the ocean’s edge and the new open-air stadium, built to host the 2010 World Cup matches, needed to shield soccer and rugby fans from the unrelenting winds. Completed in April 2009, its materials also had to withstand the Windy City’s corrosive port environment. Equally important was that the Nelson Mandela stadium have a post-World Cup life, one that would benefit Port Elizabeth. No white elephants here. The sustainable structure also had to have an aesthetic presence that would contribute to the city’s architectural environment.

The solution is a strikingly beautiful design whose unique, almost corrugated form effortlessly wraps over the pedestrian concourse circling the stadium and the seating within. Elegant but straightforward, the design was based on the principles of a suspension bridge and an arch bridge and was a joint effort between GMP Architekt, Berlin, engineers Schlaich Bergermann und Partner, Stuggart, and subcontractor BirdAir Inc., Amherst, NY. The sophisticated structural design eliminated the need for secondary girders that often block sightlines. The tensile roof system features two alternating cladding materials: perforated aluminum and a white PTFE-coated Fiberglas® membrane. Uniquely, the aluminum covers the primary truss system on the interior. “The design does not showcase the structural elements as in many stadia,” states Knut Göppert, the lead engineer. “The design showcases the open space, the area in between the structural elements.”

According to Göppert, the PTFE membrane was the logical fabric of choice. “It has a long life span and needed to be essentially maintenance free. And it needed to have solar capabilities,” says Göppert. “The benefits of the membrane outweighed any cost considerations.”

From the exterior, the alternating aluminum and membrane creates a rhythm of light reflection and absorption and also one of surface texture. The opaque perforated aluminum reflects the sunlight and the translucent PTFE membrane allows daylight to illuminate the interior concourse. “It is an interesting and unique visual play of materials,” adds Göppert. About 22,000m2 of membrane was used in the cladding system and constituted approximately 10% of the overall roof material. The membrane constituted approximately 20% of the roof budget and roughly 4% of the total project budget of roughly 22 million euros.

Göppert describes the design as elegant and economical. “We optimized the design. It looks quite complicated but the design is really very simple without looking simple,” he says. “And the sports fans will be protected from the wind.”

Mason Riddle is a contributing editor for Fabric Architecture.

Atlanta’s Georgia Dome establishes a number of new fabric-roof records

Fabric Architecture | January 2010

By Gene Rebeck

Call the 70,500-seat Georgia Dome a domed stadium, according to its designers, and you miss the point. To understand how, you first need the answer to a key question: Why a dome in Atlanta?

Although many domed stadia have been built in warm climates —Houston’s Astrodome, New Orleans’ Superdome— most have been built in colder or rainier areas (Minneapolis, Detroit, Seattle), where inclement conditions can cost unprotected sports teams cash-paying fans. But why would warm, sunny Georgia need a domed stadium of its own?

Because in a very real sense, the Georgia Dome is not a domed stadium. “The Georgia Dome is a building, not just a stadium with a roof,” asserts Scott Braley, AIA, the structure’s project director. “It’s a building with a stadium inside.” The Georgia dome doesn’t look like any other domed stadium. The typical “dome,” however ingenious its engineering indoors, tends to present a utilitarian, almost Brutalist face to the public. Come in, stay outside, don’t matter to me, these exteriors seem to say. This probably isn’t the architects’ fault: Design money, like hot air, seems to float up to the ceiling, leaving a façade that is little more than an ugly precast-concrete blank.

Not so the Georgia Dome. Attached to the Georgia World Congress Center in downtown Atlanta (the Omni Center and Cable News Network tower are nearby), the Dome will play a key part in an exhibition and convention complex. Housing sporting events is only one of the Dome’s purposes. The stadium will play host to Atlanta Falcons football games and the Peach Bowl; however, it also can accommodate other functions where its big seating capacity can be put to use—concerts, exhibitions and big conventions. A huge unattractive football stadium would work against the surrounding buildings and against its magnetic pull for big events.

Instead of concrete, the dome’s rectangular, 25-story exterior is clad in composite metal panels, whose electrostatically applied palette of plum, blue-green and white pick up tones from the surrounding structures and the dome’s white roof. Curtain walls of green glass appear at the truncated corner entrances. Inside, rings of restaurants and pedestrian concourses also help underplay the structure’s sporting function.

But the project’s distinctiveness doesn’t end there. The Georgia Dome possesses the world’s largest cable-supported roof, measuring 235m by 186m. Further, it is the world’s first large-scale oval dome. Its cabling system and its shape give the roof a remarkable texture, a tent-like ambience with an almost Arabic air.

Designed by engineer Matthys Levy of Weidlinger Associates in New York City, the fabric roof melds Buckminster Fuller’s “tensegrity” concept with the hyperbolic parabola, the “building block” saddle shape of tension structures. Levy calls his design “hypartensegrity.” From Fuller comes the idea of a triangulated membrane in which “islands of compression reside in a sea of tension.” The fused triangular panels of the Georgia Dome are tensioned using cables. These cables also hold aloft a series of three oval-shaped concrete “tension rings,” elliptical about the roof’s two focal points. Each of these rings, along with the cabling, supports numerous steel support posts that provide upward compression. The posts hold up the roof like columns, except that they do not reach to the ground. Thus, spectator views of a speaker or a game are unobstructed.

For extra load support, the triangular fabric panels form diamonds that are saddle-shaped (hyperbolic paraboloid). Pulling together the roof’s two foci is a plane cable truss 56m long. The result of all this engineering is a roof distinctive both functionally and aesthetically—this Dome aspires to be not just a dome, but a local architectural landmark.

But why fabric instead of something more “solid”? “A solid roof would be no more maintenance-free tha a steel or concrete structure,” says project director Braley. “Given that, the next factor is cost. A fabric roof is simply more economical for these spans.”

The Georgia Dome is not the first fabric tensile structure to use the tensegrity concept. The Suncoast Dome in St. Petersburg, Fla., designed by engineer David Geiger, also uses a cable/tension-ring system to hold its fabric roof aloft (FA, Spring 1990.) But in the Suncoast’s round dome, the fabric, although composed of triangular shaped panels, has not been curved into saddles, and its cabling is radian from the central ring. “Mine is totally triangulated,” says Levy. “The stress is completely on the cables, rather than having any on the fabric.”

Even the Georgia Dome’s architectural team, Heery/RFI/TVS, has a distinctive structure. Various members of three firms—Heery International Inc., Rosser Fabrap International and Thompson, Ventulett, Stainback & Associates—combined to form a ‘mini-firm’ autonomous in its separate office. Duties were not divided between members of each firm but overlapped holistically, cooperatively.

When completed, the Georgia Dome cost more than $200 million and covers about 6 hectaires. About 10,000 parking spaces are located within three blocks, with MARTA, the local mass-transit system, serving the Dome at two stations.

Besides the Falcons games and the Peach Bowl, the structure housed events for the 1996 Summer Olympics. Not bad work for a building that isn’t a stadium.

Gene Rebeck was the first editor of Fabric Architecture magazine. This article ran in the May/June 1992 issue.

New York City’s urbanSHED competition invited designers to propose alternatives to the ubiquitous grimy, dark sidewalk scaffolds that blight the city

Fabric Architecture | January 2010

If Kevin Erickson, of KNEstudio, New York City, had his way, all of New York City would benefit from the addition of “clouds” of air-inflated ETFE beams as replacements for the usual grim sidewalk sheds that purport to protect pedestrians from falling debris at downtown construction sites. Erickson’s design team suggests that their design would encourage more public participation in street life because of increased daylight that would filter down through the translucent ETFE beams and the glow at night (the beams would contain LED lights).

KNEstudio’s proposal, “urbanCLOUD”, is one of three finalists for the urbanSHED international design competition sponsored by the New York City Buildings Dept. and the AIA New York Chapter calling for innovative ideas to improve the city’s streetscape.* KNEstudio’s design takes advantage of ETFE’s high strength-to-weight ratio that permits its pneumatic structure to be suspended from the roof using standard outrigger beam systems commonly used for skyscraper window washing. A series of air beams are stacked to create a continuous shelf of protection along any building façade. Internal cables to the air beams constrain the expansion of the air tubes to give the system a cloud-like form. By controlling the air volume in each beam, and thus their shape, the beams can adjust to accommodate site conditions such as trees, elevation changes in building façades and other urban anomalies. Rather than building from the ground up, ubranCLOUD hangs from the top down permitting the free flow of pedestrian traffic at sidewalk level.

Both of the other two finalists of the competition include textile elements in their designs. Young-Hwan Choi, of the University of Pennsylvania, Philadelphia, Penn., designed a series of umbrellas—alternating inverted and upright positions—using carbon fiber in the support columns. A team from Brookline, Mass., XChange Architects, proposes a portable structural system using a tripod-like module with recycled PVC fabric screens on the underside of the canopy to conceal the substructure. At press time, the final selection of a design to be implemented had not been made by the jury.

* Additional sponsors include the Alliance for Downtown New York, the New York Building Congress, Illuminating Engineering Society New York Chapter, and the ABNY Foundation.

Fabric Architecture | January 2010

Dutch industrial designer Axel Enthoven has designed a new mobile home inspired by the Sydney Opera House. In fact, the fabric and stainless steel trailer has been christened “Opera” in recognition of its design roots. Developed in cooperation with Rob Vos, who conceived the idea, the Opera trailer tent opens and levels itself in five minutes by electric motors and when fully extended measures 7m by 3m by 3.5m high. A true luxury item, Opera comes with two electrically adjustable beds, running water, toilet, LED lighting and a portable grill, and is fitted out with a wine cabinet, espresso bar and an enclosed teak veranda. A limited number of the mobile tents will be produced in 2010.

Fabric Architecture | January 2010

Every two years, a landscape architect is chosen through a juried competition to create an installation for the Cleveland Public Art Park. The 2009 incarnation, from Eventscape, Toronto, Ont., Canada, celebrates both Cleveland’s industrial heritage and its new “green” environmental agenda. The fabric-clad organic futuristic forms make a powerful visual impact on a number of levels: historic, artistic, structural and political.

The fabricated steel forms represent the city’s historical steel industry. The hand-bent frame was requested by the project designer to enhance the organic feel.Ê

Each element required integrated solar panels to give a luminous glow to the fabric structures at night. The custom covering was fabricated to match the client’s green color, and is coated for water repellency and UV protection. Eventscape worked closely with the client and fabric mill to find a material that would meet requirements for stretch and translucency as well as lightfastness and weathering criteria. In winter, the outer fabric covering is easily removed to showcase the metal armatures’ structure, casting intricate shadows and providing two design options for this all-season attraction. Design is by North Design Office; Peter North, for Cleveland Public Art. Engineer for the project is Ian Mountfort with Blackwell Bowick Partnership Ltd.

Feb. 4–April 2, 2010, New York City

Fabric Architecture | January 2010

The innovative, award-winning and environmentally conscious architectural firm Snøhetta, is featured in a multi-faceted exhibition at Scandinavia House: The Nordic Center in America. The exhibition presents a selection of the firm’s work, including the air-inflated Kongsberg Jass Festival Tubaloon fabric structure shown above.

Fabric Architecture | January 2010

In Suzhou, China, Harmony Times Square, next to Suzhou Industrial Park Jinji Lake, is a new landmark for the city, including office buildings, retail streets, riverfront cafes and a state-of-the-art shopping mall. Its urban design and open canal-side streetscape create a cultural center for the city, and also serve broader needs by integrating expansion and transportation requirements. A variety of bridges, pathways, plazas and retail tenants frame the unique development; the complex also includes a river shuttle service, an air corridor served by an ultra-large square, six subway exits and more than 4,000 underground parking spaces.

The sky canopy adds a unique element to the experience, with multimedia projection surfaces connecting the low-rise retail buildings along the river. Roofed with 292 ETFE air cushions, with five air supply machines to guarantee a permanent source of inflation, the canopy has a PTFE-coated open-weave glass fiber fabric structure directly under the roof, on which approximately 20 million LED lamps are installed, to form what is claimed to be the world’s largest LED display screen. Designed by HOK (Asia Pacific), engineered and fabricated by covertex membrane (Shanghai) Co. Ltd., the canopy has a waved aluminum panel edge and is supported by steel tube pillars. (The PTFE mesh underneath was subcontracted to Beijing N & L Fabric Tech Co. Ltd.)

The soft, shining lights of the sky canopy are “like a shining color stripe floating beside the Jinhi Lake,” combining aesthetics and technology to represent the modern world. The project won a 2009 Award of Excellence in IFAI’s annual International Achievement Awards program. View all the winners at www.ifaipublications.com/iaa.

Fabric Architecture | January 2010

Dublin’s U2, recognized worldwide for its driving yet melodic musical vision, launched the band’s “360° World Tour” in June 2009 on a fabric-clad stage that rocks around the clock. The stage system resembles a giant steel-trussed spider clad with PVC-coated polyester blackout fabric. No matter where concert goers sit, even if the venue is a giant sports arena, the band is visible—and the stage riveting.

Band members worked with architect/designer Mark Fisher Studio in early stages and wanted the steel trusses covered. Architen Landrell, Chepstow, U.K., a manufacturer of tensioned-fabric structures, obliged with fabric of a specific color chosen by the band and the flexibility to capture the complex geometry of the design. The center of the structure contains a vertical LED-lit pylon and a retractable video screen. The company completed the stage’s tensioned fabric cover within nine weeks, a fast turnaround for the 360° World Tour that will continue into 2010.

A south Florida awning company takes its own advice and installs a new entrance shade canopy; customers take notice

Fabric Architecture | January 2010

The main purpose of the tensioned-fabric canopy above the entrance to Hoover Canvas Products Co., of West Palm Beach, Fla., is to catch the eye of passing motorists. It works; people began taking notice soon after the canopy went up.

Additional functions also are served, such as expressing a range of possibilities for designing with fabric. “We wanted to show potential clients a number of different methods of construction and so designed the canopy to include several ideas,” says Jim Carroll Jr., president of the family-owned awning company. Two tensioned triangular pieces flank a more traditional framed canopy, acting like flying wings. These two colorful elements—or “sails” in industry parlance—shout out their nautical heritage with steel clamping plates at each point of the triangles, giving a sense of energy and movement to the entryway composition. Fabrication of the sails is consistent with standard tension structure detailing with stainless steel edge cables held in place by sewn pockets and terminated with threaded tensioning ends welded to the clamping plates to properly tighten the edges. The clamping plates are attached to anchor points at the top of two splayed columns and at points on the façade.

A more traditional framed canopy is tucked under the two sails, its gently arched front truss supported by the two splayed columns. Fabric is held taught against the curved truss and guyed back to the building with more tensioned cables, but in this case the cables are exposed and the fabric edges are fastened to the cables with rings spaced evenly along the length of each cable. The front edge of the canopy is laced to the top cord of the arched truss, and the top edge that meets the building façade is clamped to the building by a luff track to make it watertight above the entry doors.

Thus, says Carroll, in this one structure clients can find many kinds of fabrication methods that Hoover has successfully executed, a handy sales tool and a full-size prototype for future projects.

Anish Kapoor sculpture blends fabric and steel in New Zealand

International sculptor Anish Kapoor stretches fabric and steel to manipulate views of the New Zealand seascape

Fabric Architecture | January 2010

“I am interested in sculpture that manipulates the viewer into a specific relationship with both space and time.” –Anish Kapoor, Tate Magazine, July 2007

The Indian-born artist Anish Kapoor is probably best known in the United States for his 2004 chrome installation piece “Cloud Gate” for the Millennium Plaza in Chicago, but Europeans—especially Londoners—will know him for his massive, bloodred, site-specific sculpture “Marsyas” displayed in the Turbine Room of the Tate Modern during its grand opening in 2002. Kapoor appreciates what engineers and tensile fabricators do because it affects his work: “I am concerned with the way in which the language of engineering can be turned into the language of the body,” he says. “Marsyas” relied heavily on the skills of both Arup for the engineering and Bo Hightex for the piece’s fabrication. (See FA, May/June 2003, p.22.)

Although the Tate sculpture was temporary, Kapoor often creates his outdoor sculptures for permanent residence. Such is the case with his recent installation for “The Farm,” a 400ha (1,000 acre) private estate outdoor art gallery in Kaipara Bay, north of Auckland, New Zealand. Kapoor’s first outdoor sculpture in fabric, “The Farm” (the sculpture is named after its site), is designed to withstand the high winds that blow inland from the Tasman Sea off the northwest coast of New Zealand’s North Island. The sculpture is fabricated in a custom deep red PVC-coated polyester fabric by Ferrari Textiles supported by two identical matching red structural steel ellipses that weigh 42,750kg each. The fabric alone weighs 7,200kg.

The ellipses are orientated one horizontal, the other vertical. Thirty-two longitudinal mono-filament cables provide displacement and deflection resistance to the wind loads while assisting with the fabric transition from horizontal ellipse, to a perfect circle at midspan, through to the vertical ellipse at the other end. The sculpture, which passes through a carefully cut hillside, provides a kaleidoscopic view of the beautiful Kaipara Harbor at the vertical ellipse end and the hand contoured rolling valleys and hills of “The Farm” from the horizontal ellipse. Fabrication and installation of the art piece is by Structurflex Ltd., of Henderson, Auckland, New Zealand, overall engineering is by Structure Design Ltd., membrane engineering by Compusoft Engineering Ltd.

FabricArchitectureMag.com | December 7, 2009

By Mark Zeh

Last September, as the strength of the current financial crisis was still revealing itself, 13 architecture students at the Harvard University Graduate School of Design began a provocative one-semester studio program titled GINA Studio. The program was undertaken as part of a $1.5 million endowment from RMJM Architects, a UK-based international architecture firm with U.S. headquarters in New York City, to establish the "RMJM Program for Research and Education in Integrated Design Practice." The intention of this endowment was to address the need for an expanded curriculum in the teaching of the practice of architecture. RMJM's endowment was matched with $500,000 from the Harvard Graduate School of Design.

"Our intention was to create synergies between design and architecture with our endowment," states Peter Schubert, North America design director for RMJM Architects. "It's not news that architecture anticipates automobile and product design-architects just haven't taken full advantage of that yet. Working with students is always inspirational, since their thinking isn't constrained with any knowledge of building codes, materials properties or the limitations of contractors."

The GINA Studio was the result of conversations between Chris Bangle, then chief of design for BMW Group, and Frank Barkow, one of the principals at Barkow Leibinger Architects in Berlin, Germany. Both were curious to work with students to find new applications outside of the automobile business for the membrane technology that had been developed for the BMW GINA concept car. GINA is an acronym that stands for "Geometry plus an Infinite Number of Adaptations."

"Frank and I met when he had won the competition to design BMW's Design and Concept Center. Unfortunately, the building has remained unbuilt, for a variety of reasons," Bangle states. "During the process of commissioning the work, I'd spent quite a lot of time talking with him about the GINA philosophy (at the time the concept car still hadn't been revealed to public), which was driving a lot of our design thinking."

"After the BMW Design Center project was put on hold, we'd again met in Berlin. During that meeting, Chris and I talked about the relevance of revisiting Frank Lloyd Wright's seminal 'Broadacre City' vision," Barkow says. "Wright's concept had been a new form of living, where integration of the auto into city planning enabled homes to be built on large lots far from the urban core. Mixed land uses were envisioned for the one-acre allotments for each housing unit. Of course, suburban allotments ended up being a lot smaller, so a number of the potential benefits of Wright's concept were never realized. We felt that the philosophy of flexibility underlying the GINA Concept was a good basis for re-imagining the American suburb and the relationships between people, houses and automobiles. We were challenging the students to create more-relevant suburban spaces, within the current sustainability and economic contexts."

Barkow handled the day-to-day teaching duties of the class, while Bangle assisted him and reviewed the student work. "My role was really to shake things up," Bangle explains. "I only visited the students about four times during the studio, so I introduced them to the GINA Philosophy and showed them presentations about the technology and concept films about how it could work and so on. My role was really to show them information from the viewpoint of a car designer."

The timing of the program turned out to be very good, with respect to providing students with strong external context to rethink the suburb and the way people live. "I was literally standing in front of the students, showing them newspaper headlines like 'American Suburbs Dead,'" Bangle says. "It's hard to exaggerate how extreme things were starting to look in the fall of 2008."

We'd decided to emphasize the sustainable and adaptable aspects of the GINA Philosophy and technology," Barkow says. "Remember that at this time, gasoline was $150/barrel and issues of environmental control, energy efficiency and sustainability had become serious topics of conversation."

The studio yielded fantastic work and introduced some themes that are powerful in digital culture now. "There was a concentration of work around the theme of expandable, adaptable modular base units that seems like it's tied to the Transformer culture," Schubert says. "I was also impressed with the redefinition of modularity that the students expressed. In the past, modularity was about efficient use of materials and mass-production methods. Now the students are using it as a means of controlling their environment and as a means of personal expression."

"One of the most powerful take-aways that I got from this work is that using the ideas of flexibility and movement, the house becomes a conduit to understanding your environment," Bangle says. "Another was that flexibility could enable social interactivity with your neighbors. There were scenarios where one person's wish for a particular configuration may overflow into the volume occupied by a neighbor's house, requiring negotiation between the neighbors."

"Kinesis is really the Utopia of architects," Barkow says. "A flexible skin that controls the building climate and light levels enables new kinds of relationships between people and their spaces. The students really embraced the power that digital fabrication and production gives the architect. Now mass-production doesn't mean Levittown-style, cookie-cutter houses anymore-this technology really enables mass customization."

"The materials palette will require more development to enable any of this, though," Barkow says. "There's just nothing around that can be applied in an architectural context, or even in the original automotive context, that has these performance properties yet. There's actually quite a limited number of materials available to architects working with membrane structures."

The GINA Studio was a one-off class at the Harvard Graduate School of Design. Both Barkow and Bangle said they'd enjoy the chance to repeat the experience.

"I'd like to see the work from this studio supported with a longer-term engineering project, to give it some teeth," Bangle says. "To me, it would also be interesting to free the students up to take more chances-they took their work very seriously. I can imagine developing this studio further," Barkow says. "It would be better to do it over two semesters, with the students delivering films at the end. That would give the students more time for concept development, rather than putting the focus on creating the deliverables."

Mark Zeh, a consultant in product innovation and management, is a regular contributor to Fabric Architecture. He writes about design and architecture from Munich, Germany.

How to keep membrane materials looking new over time.

Fabric Architecture | November 2009

By Mark Zeh

Unlike Henry Ford, who claimed you could get his automobiles in any color as long as it was black, fabric structures do come in more than one color. However, sometimes these alternate colors are unintentional. Here are several tips on keeping things looking new over time.

“You must remember, these materials have really only been around for about 50 years,” says Georg Lind, executive vice president of the roofing business unit of Sika, Germany. “When we look at the history of the development of membrane materials used in construction, we see continuous development to increase performance and longevity in the outdoor environment and reduce costs of production, installation and maintenance. Since these things are still evolving, there hasn’t been a lot of investment in texture and color. The investment in design that has been made has been in areas such as increasing transparency or transmissivity and the development of non-stick or self-cleaning coatings.”

By the looks of it

Recently, my wife and I were driving past the new BMW Museum and the Olympiapark in Munich, on the Georg-Brauchle-Ring. As we discussed how the BMW Museum complements the Olympiapark and how the Olympic grounds (completed in 1972) still look futuristic, I spotted the weathered roof of the Eisstadion (Ice-skating stadium—now the SoccaFive Arena) near the eastern end of the park. Dr. Rosemarie Wagner, architecture professor at the Fachhochschule Munich, says this is one of the oldest membrane roofs in Munich, so I was prepared to see something showing some age, but I found the condition of this structure surprising since the tension structures in the Olympiapark are considered to be part of the architectural treasures of Germany. This prompted me to consider how membrane materials age and patinate and how aging affects a lightweight fabric structure over its life cycle.

My interest in how architectural materials age and patinate first came to me in 2007 when I visited Santiago Calatrava’s Ciudad de las Artes y las Ciencias (City of Arts and Sciences) in Valencia, Spain. From my point of view, he seems to have envisioned an optimistic sprawl of pristine glowing white forms shining in the sun, in a dry river bed in Valencia. Many of the surfaces include glossy white tile shards, so the forms appear ultra shiny. The buildings are surrounded by reflecting pools to create excitement from how the lighting plays on the surfaces of the structures and to build a sense that the structures are “places” apart from the surroundings.

Ciudad is fantastic and impressive on almost every level. However, on my first visit, as I got closer and started poking around, I realized that it is already looking worn and that the city has already had to repaint and restore things (the pools around the Opéra [opened in October 2005] were dry both times that I visited in 2007 and the Opéra building itself was undergoing some façade reconstruction.) One difficulty is that everything is white, leaving clear witness when soot from diesel vehicles and many industries around the city falls on the structures and dirty rainwater runs off of their surfaces.

It is educational to compare the appearance of the surface materials used in the Ciudad to those of some traditional materials, such as marble, copper or zinc-plated steel. These traditional materials tend to develop character as they acquire various patinas, up until their replacement points.

PVC-coated polyester compared to ETFE

With these observations in mind, let’s review some of the older membrane structures in Munich with the original architects and other interested parties. We’ll compare two structures roofed in PVC-coated polyester and review one structure roofed in ETFE. Coincidentally, all of the roof structures were fabricated by Koch Membranen of Rimsting, Germany.

The architect for the ice-skating stadium in the Olympiapark is Kurt Ackermann of Ackermann und Partner in Munich, Germany. It was roofed in white PVC-coated polyester by Koch Membranen in 1984 and was completed in 1985. I’ve visited it a few times over the past months. From a distance, there are lots of noticeable water runoff paths and large discolored areas. Moss and lichen growth on the seams, fasteners and edges are visible at closer distances. I spoke with Hans-Juergen Koch, managing director of Koch Membranen, about how this structure has weathered.

“Since PVC has a relatively high surface energy, it tends to attract dust and pollutants,” he explained. “Since the ice stadium was roofed, acrylic and flouro-top coats, with non stick or self-cleaning properties have been developed for PVC-coated polyester membranes. These coatings also help in limiting the migration of plasticizers out of the material, helping to reduce the factors leading to discoloration. That said, we have to keep in mind that this roof is 25 or 26 years old now. It has well exceeded its 15-year guaranteed service life.”

Peter Ackermann, partner at Ackermann und Partner, added, “The structural portion is composed of steel cables and wooden strips. The PVC material is just a rain cover fastened to the wooden strips and was quite inexpensive at the time. This was also a relatively new application for this material; it was originally developed to cover flat roofs. After quite a lot of debate during the design process, PVC-coated polyester was selected with the assumption that it would be replaced after its 15-year service life. It’s remarkable that the material is still weather tight, but it’s also a bit of a shame that it hasn’t been replaced, since it looks so bad now.”

Dipl.–Ing. Wasem Ajmail, project leader for maintenance of the structures in the Olympiapark for the Stadtwerke München, GmbH (Munich City Utilities), explained why the roof hasn’t been replaced. “We’ve tested the roof of the ice stadium and it is still sound,” he said. “The performance of the material has been so good that we shouldn’t need to make a decision about replacing it until 2011. At that point we’ll reach a decision about whether to replace the roof or put an entirely new structure on that site.”

“The roof is very weathered,” says Ajmail, “but it’s just not possible to clean it without damaging the membrane material.” Dr. Wagner has an explanation for this. “UV light acts to break the polymer chains in the PVC allowing the plasticizer to escape, leading to the material becoming brittle over time. Mechanical vibration from the wind and thermal expansion and contraction combine with embrittlement to create small cracks in the surface, allowing water to wick into the fibers, leading to staining. Also, particle buildup on the surface creates areas that heat up with the sun’s energy, compounding the cracking and staining problems.”

It’s interesting to compare the ice stadium with the rhinoceros house in the Hellabrunn Zoo in Munich, which was completed in 1988. Stefan Endl of R.E. Architekten from Schaeftlarn, Germany, then working for Büro Herbert Kochta, Architekt BDA (now Kochta Architekten) of Munich, was the architect responsible for this structure. Like the ice-skating stadium, it is roofed with a PVC-coated polyester material that is not bearing any structural loading, but this membrane is dark green and is draped over a concrete shell structure.

The level of particle accretion, staining and moss and algae growth seems similar to that of the ice-skating stadium, but the fabric color and the original color choices and patination of all of the materials in the structure combine to produce a settled, organic impression not unlike that of a heavily oxidized copper roof.

When I spoke to Endl about this and showed him some recent pictures, he was surprised. “We had originally proposed that the roof be a warm grey or light blue color, but the people at the zoo insisted we go with this dark green color,” he explained. “Originally, the roof material was a glossy dark green, with light turquoise-colored tensioning buttons. It was supposed to look organic, a bit like a fly agaric mushroom emerging from the ground. I haven’t seen it in about 10 years, so I’m a bit surprised about how it has changed and that the original material is still in place. It’s interesting that it has weathered to this appearance since we developed the panel and joining geometry to reference the look of lead roofing.”

Kochta further explained, “This was a relatively new application for the PVC-coated polyester material and it required quite a lot of development and improvising to use it in this three-dimensional application. There are many things we could have done differently, but I have to say that I am quite satisfied with how it looks and how it has aged.”

The Jungle House at the Hellabrun Zoo is also from Kochta Architekten. It was finished in 1993. The roof of this structure is formed from pressurized ETFE air cushions in a framework of metal cables and channels. The surfaces are still very glossy and transparent. Up close, it shows evidence of some puncture repairs, a bit of condensation or algae growth inside the cushions where airflow doesn’t remove all the moisture, and minerals and dirt on the surfaces, but this isn’t objectionable and could probably be removed with a cleaning process.

Dipl.-Ing Architect Eduard Lehner, now managing director of DBLB Architekten + Ingenieure of Munich, worked on this during its final design stage and construction. “I’m still very satisfied with how this structure turned out,” he says. “This was one of the earlier uses of ETFE in this sort of application, but it really isn’t a surprise that it has maintained its appearance so well. The material doesn’t really patinate since it doesn’t oxidize, doesn’t change with exposure to sunlight and it has self-cleaning properties. It’s supposed to be guaranteed for 30 years, but I won’t be surprised if it lasts much longer. At the time that we developed this, one of our major concerns was whether or not the material would maintain its degree of transparency over time. I recall that Koch conducted artificial aging tests to try to determine this.”

“I’m also still very satisfied with how this structure looks. This is really the perfect application for ETFE too,” adds Kochta. “The Jungle House is really a large greenhouse and ETFE film has very high admissivity for UV light. I think the only performance and appearance risks in using this material are that algae will grow inside the cushions without proper airflow.”

To sum up, it seems that there are a few important factors to consider in designing a membrane structure that will age well. Among these are initial color choice, retention of solids on the surface and regular maintenance of the structure.

Mark Zeh, a consultant in product innovation and management, is a regular contributor to Fabric Architecture. He writes about design and architecture from Munich, Germany.

SpecialtyFabricsReview.com | November 12, 2009

Upper South Studio, Winston-Salem, N.C., has announced the expansion of its company, adding three new divisions to meet the growing interior design and sourcing needs of commercial and residential designers, purchasing agents and architects. Upper South Studio companies have been known for 30 years for the custom design of fabric for the international hospitality, gaming, corporate, spa, health care, restaurant and travel industries.

One of the new divisions, Upper South Re:source, offers efficiently sourced textile materials and creative design solutions to meet the pricing, utility and aesthetic needs of design offices and purchasing agents for commercial interiors.

“A company like Re:source has become a unique need of the trade,” says Susan Rosen, chief operating officer of Upper South Studio. “As the textile industry struggles in the challenging economy, there is huge demand for sourcing of fabrics to meet project specifications; and little time for purchasing agents to fulfill their requirements.” Rosen asserts that the new division helps agents by offering connections to mills and fabricators, while striving for high quality and standards.

FabricArchitectureMag.com | November 6, 2009

Universal Fabric Structures (UFS) has announced the launch of its new custom architectural division, Fabritecture.

UFS’s goal is for Fabritecture to set a new benchmark in fabric structure design and construction, providing solutions for developers, builders, governments and private contractors who require custom projects.

Fabritecture will operate in tandem with UFS, which will remain active to provide a wide range of pre-engineered fabric structures.

An open-air pavilion provides form and function for students and community alike

Fabric Architecture | November 2009

By Abbie Yarger

Richard and Pat Lawson made history at Oklahoma Christian University, Edmond, Okla., by pledging the largest alumni gift, $30 million, to the school in 2004. To honor their generous contribution and distinguished alumni status, the university requested the construction of a unique structure that would embody the many aspects of student life.

The university turned to TAP Architecture, a firm located in Oklahoma City, Okla., to work on the 720m² Lawson Commons pavilion connecting university housing to the bustling student center. Along with providing a passageway for students, the university wanted to create an outdoor space where formal events and ceremonies could be enjoyed by university faculty and guests, as well as the local community. “The client’s close involvement in a long-range design process resulted in a truly successful outcome,” says Anthony McDermid, AIA, RIBA, principal architect of TAP Architecture.

To achieve the desired campus enhancements, TAP collaborated with Birdair Inc., Amherst, N.Y., to design the pavilion with a tensile structure to shield guests from the elements. The roof is made of Sheerfill® II fabric, which deflects solar energy and emits low levels of heat. “The fabric cover provides protection from Oklahoma’s sometimes hostile sun and rain but celebrates long light days and constant cooling breezes,” McDermid says. “The pavilion can be occupied in all but the most adverse of weather without any energy consumption.”

In addition to preventing the heat island effect and cutting down on energy costs associated with traditional event venues, the structure captures rainwater runoff to deter water from pooling on the roof. Excess water is routed from the corners of the structure to nearby landscaping, creating an eco-friendly irrigation system. Strong column structures keep the fabric stretched to proper tension, keeping the roof securely in place. During the construction of the structure, special attention was paid to the details of the bolts, which were installed to meet the safety and aesthetic demands of the design.

The pavilion received extra attention when the Lawson Commons project was named an official Oklahoma Centennial Project for vastly improving the university campus. The project also included new landscape and hardscape of the three-tiered mall area, as well as the erection of the Centennial Clock Tower, which spans 30.5m tall in juxtaposition with the pavilion. Several student activities and community events, including wedding ceremonies, are now held at the pavilion, which has been booked since the completion of the project. “The pavilion is essentially a student-centric space,” McDermid says. “It is playful, elegant, practical and, most importantly, has created a sense of place.”

Abbie Yarger is a freelance writer and editor based in Minnesota.

The city’s new convention center brings together waterfront and city

Fabric Architecture | November 2009

By Mason Riddle

There are green roofs and then there are green roofs. The new Vancouver Civic Centre West (VCCW), completed last April, boasts a Goliath of a green roof that covers a whopping six acres making it the largest in Canada and the largest nonindustrial living roof in North America. Comprising two tiers, one of which is accessible to the public, the green roof is planted with more than 400,000 indigenous plants and grasses—most of which will seasonally replant themselves, creating a natural habitat for birds, bees, butterflies, insects and small mammals. The roof also supports four hives, each of which is home to 60,000 bees whose honey is used by the Centre’s kitchen. The living roof was also designed to serve as an insulator against summer heat gain and winter heat loss. Its configuration is sloping and fractured simulating natural landforms. Its angled sections are interspersed with glazing that allows visitors to view the living roof from the interior. The VCCW also extends over the water creating tidal zones underneath that flush daily with the rise and fall of the tide.

The VCCW is a key—and final—piece of the Vancouver’s large, comprehensive waterfront development plan. Its site was the last waterfront real estate not yet part of the city’s public realm. More than 15 years in the design and making, the building is the result of a multidisciplinary design team led by Mark Reddington of Seattle-based LMN Architects in collaboration with Vancouver-based Musson Cattell Mackey Partnership and DA Architects & Planners. Explaining the design process, Reddington states, “We needed to define how the city actually meets the water and how the building could incorporate that and still be part of the public realm. It’s where the water meets the land. The Convention Centre plays a huge role in Vancouver’s waterfront space yet it still needs to function as a convention center.” LMN and the city have applied for LEED Canada Gold. In 2010 it is also serving as the international broadcast and media center for the 2010 Olympic and Paralympic Winter Games, housing more than 7,000 media personnel who will broadcast globally.

To create a comprehensive and sustainable building design, Reddington and his team expanded the typical convention center agenda to include the adjacent public parkland, the rehabilitation of the surrounding natural waterfront habitat, incorporation of the spectacular mountain and marine views, and an integrated green roof, all in a holistic and multidisciplinary approach. In addition to horticulturalists, the design team included marine biologists who developed restoration plans for 60m of shoreline and 457m of marine habitat. “We needed to understand how all of the different systems of the city, the land, the water intersect,” states Reddington. “The basic idea was how to make it really part of the landscape and still function as a major part of the city.”

Not surprisingly, water plays a big role in the buildings design and living roof. An integrated irrigation system keeps the rainwater on the roof for as long as possible. Excess rainwater runs into drainage channels and is reused to irrigate it. The building’s black water treatment system processes sewage for other uses and provides about 80% of the gray water needed for toilets and irrigation of the living roof. In drought conditions, the building can harvest sewage water from the city. A desalination plant draws water from the harbor and processes it to supply additional nonpotable water demands. A seawater heat pump system takes advantage of the constant temperature of adjacent seawater for irrigation of the living roof.

One of the design questions was how the building was to visually and materially relate to the earlier Vancouver Convention Centre East (also called Canada Place), which was built in the late 1980s. The latter has a notable tension fabric roof. The conclusion was not to compete with or dilute this aesthetically unique element of the existing east building. Reddington believes that the complex benefits from the juxtaposition of the two aesthetically different buildings.

The VCCW project encompasses 108,000m2, 36,000 of which is walkways, bikeways, public open space and plazas. One end of the 4,950m2 ballroom is floor-to-ceiling glass, affording spectacular views of the water and mountains beyond. Acoustic wall panels are made of fabric and ring the perimeter of the expansive space. “The wall of glass is one of the most dramatic things about the design. It’s the most dramatic setting for a convention center in the world,” says Reddington. Local materials were used throughout, including hemlock-clad walls and Douglas fir slat ceilings harvested from Vancouver Island and the Sunshine Coast. Indoor air quality is high due to a natural ventilation system.

For Reddington it was rewarding to see the building finally open to the public. “For so many years it was a set of ideas, issues and plans,” he says. When it finally opened it became part of the city.” Indeed it did. The weekend of the grand opening, more than 65,000 people came through its doors, claiming it as theirs, christening it as part of Vancouver’s community life.

“We’d like to think of the Convention Centre West as part of citymaking, not building-making,” adds Reddington. “Using ideas of sustainability and urbanism, we are making the world in a responsible, more progressive way.”

Mason Riddle is a contributing editor for Fabric Architecture.

A winning retail design in Vancouver

Fabric Architecture | November 2009

By Jeremy Clark

Olympic spirit is riding high in anticipation of the 2010 Winter Olympic Games in Vancouver, British Columbia, Canada. And who better to be named the official store for 2010 Winter Olympics merchandise than Hudson’s Bay Company (HBC), Canada’s first and most famous department store. HBC was established in 1670 and is Canada’s largest department store retailer, and its oldest corporation. It is also one of the premier sponsors of the 2010 Winter Olympics. HBC’s new shop within its downtown Vancouver flagship store covers two-thirds of the main floor with an exciting environment flush with Olympic colors.

The centerpiece of the shop is a 21m long by 4.5m high curved wall with three polished steel archways that suggest the three Olympic medal standings. The S-curved walls, which hold stunning graphic images of winter sports, make a dynamic backdrop for official Olympic clothing and accessories. Multiple materials were chosen to make the massive structure strong yet lightweight enough to achieve the designers’ intention to have the wall suspended in way that makes it appear to float. The three arches that act as the main support are engineered using steel reinforcements and aluminum framing. The graphic elements are modular and can be repurposed in other areas of the shop or updated with another campaign after the Games have ended. The idea of re-usability—along with lightweight, knockdown components—is in line with the goal of making the project highly efficient and ecologically responsible. The designer’s mix of materials continues in the custom millwork base that incorporates glass, colored acrylic and concealed lighting that uplights the merchandise hanging above.

A dramatic “Torch Tree” that spans 21m across the retail floor has a 4.5m high PVC-clad column/trunk (for easy cleaning and durability) with fabric-framed branches. Another featured element includes changing rooms that take the form of pods with sliding doors that display “occupied” in seven languages when closed.

The entire 450m2 space was engineered and fabricated by Eventscape Inc., a globally known designer/fabricator utilizing a vast range of materials and manufacturing techniques. The project has earned several awards for its innovation including a Grand Prize at Globalshop in March 2009, and the first ever Visual Presentation of the Year in the annual ARE Retail Design Awards. Earlier in 2009 it received a First Place at the Retail Design Institute’s 38th Annual International Store Design Awards in the category of “New Shop within an Existing Department or Specialty Store.” It also won IFAI’s Award of Excellence in October 2008 for Interior Display.

Jeremy Clark, a contributing editor for Fabric Architecture, writes frequently about product design, interiors and new materials.

Jeffrey L. Bruce, a leader on green roofs and landscape, speaks out on the promise of “Living Architecture.”

Fabric Architecture | November 2009

By Frank Edgerton Martin

Jeffrey Bruce, FASLA, recalls that when he first came to Kansas City, Mo., from New Jersey as a young landscape architect, he drove out west into Kansas to see the plains. As the sun was setting, the immensity of this open land spreading out like a giant sheet around him became so compelling that he stopped the car. “I stood on the hood for several hours and just watched the sun set,” he remembers.

Twenty years later, Jeffrey L. Bruce & Company is a pioneer in the engineering and design of green roofs and new applications for geotextiles. Working with soil scientists, architects and manufacturers, Bruce is a uniquely entrepreneurial landscape architect who not only seeks to bring the beauty of prairie flowers into city roofs, but also to invent new soil mixes and applications for existing products that will make green walls and roofs more practical in the building process.

“We hear a lot more about the landscape above the ground than below it,” Bruce says while addressing a group of water engineers in Kansas City. “Yet below the surface is where the majority of organisms live that support plant life…and green roof systems.” By speaking to engineers accustomed to piping runoff water into treatment plants, Bruce directly confronts assumptions about how to manage water in cities. “We can’t build green cities just by using less,” he says to the group. “We need to harness the power of nature to actually restore our rainwater, air and groundwater.” The idea is that landscape architecture can move to the next stage of green design by building environments, roof systems and entire watersheds that heal themselves from the effects of human demands.

The promise of green roofs for urban climates

Considering the fact that roofs cover 30% of the surface of American cities, roof gardens are one practical way to begin this embrace of restorative ecological function. The strategy of planting roofs can significantly reduce stormwater runoff and save billions of dollars in the cost of storm sewers. Facts like these get the engineers’ attention. They also merit further investigation by the industrial fabrics industry whose members can provide new materials and structural systems to support the soil profiles of green roofs and the rapidly emerging field of green walls.

The implication for designers and green industries is to think of cities as opportunities for urban agriculture and a return of cleansing vegetation. Bruce’s message to the engineers and to the well-known architects he consults is that we can never return our cities and suburbs to their fully “natural” structure. But we can learn to think of air and water as connected living systems. They are connected; they are alive.

For example, traditional civil engineering processes isolate and compact soil to build on it, but Bruce promotes a different view of soils as living communities that nourish plant growth and can detain and cleanse water to be reused on-site. Green roof systems are three-dimensional structures in which geotextiles play an essential role in separating functional layers in a “soil profile” or “soil system.” Yet, there are also constraints in the weight and depth that green roof systems add to the top of buildings.

Water is a key to keeping a landscape in hot urban setting alive. But water, if not drained properly, can add significant weight to green roofs and lead to leakage. How water moves through sand and gravel layers is key to detaining and discharging water effectively. Varying sizes of gravel can be used as layers filled with small air pockets that can retain water for slow release to support plant life. Like fine cooking, the solution lies in finding the right mix of ingredients and layers—an area where Bruce’s office carefully collects data and experiments. Geotextiles are key as a soil separator to hold these essential storage layers in place.

“We seek to capture as much rainwater on any given site—whether from roofs, hard surfaces or the soil systems,” explains David Stokes, one of Bruce’s staff landscape architects. “We’re trying to use every drop of water that falls out of the sky without releasing it to the city storm sewer system.” To further reduce environmental impact, “we do a lot of research on fabrics that are recycled or have postconsumer content,” Stokes adds.

Applied research and wholistic thinking

Generally, making a green roof investment can be challenging for builders and owners who are tempted to look first at the short-term bottom line. Yet, retaining water on-site can have significant benefits for reduced irrigation and infrastructure costs, savings that Bruce’s office continues to measure in their projects over time.

Bruce is unusual among landscape architects in that he invests time and money to perform such research. He also partners with manufacturers and soil scientists to develop and test new products. Like a true inventor, he transfers technology and solutions from one market area to another. Indeed, Bruce became a leader in green roof design because he had been working with soil systems for years in professional and collegiate sports—a high-performance design specialty where success requires sophisticated soil engineering.

Bruce’s team applies this 20-year expertise in soil design and drainage to green roofs at such landmarks as Chicago’s new Millennium Park and Soldier Field. Now Bruce’s office is applying its findings from 10 years of green roof work to other harsh city conditions that demand high-performance soils such as improved street tree planting strategies and low-demand irrigation solutions for city parks. Typical of its holistic approach, Bruce’s office doesn’t use the term “irrigation” so much anymore. Rather they speak of “water resource management.” “We hybridize solutions across practice areas,” Bruce says; and in doing so, they find new applications for erosion and water control fabrics.

Technology and products for restorative design

In the near future, Bruce’s design and applied research team is exploring three emerging technologies—nanotechnology, genetic engineering and sustainability—converging in the construction industry to create advanced composite building materials and systems. These materials will not just incorporate living ecologies as surface applications, but the building materials themselves will be restorative for air and water quality in their surroundings. Future building materials will harness and incorporate the self-healing efficiencies of natural systems as already seen in such promising advances as algae colonies that manufacture biodiesel fuels or serve as the basis for self-healing living paints.

One area where the fabric industry can contribute is in developing geotextile wall systems for holding plantings in place against buildings or as stand-alone structures. (See the profile of the green wall at the Vancouver Aquarium in this issue.) Currently, most wall systems involve some type of metal structure and trays for plantings. But given the varieties and durability of existing geotextiles and cabling systems, it’s possible that lighter and less expensive product groups can be developed.

In cities where horizontal space is at a premium, yet vertical walls are everywhere, planting upward can offer significant cooling and aesthetic benefits along sidewalks, near building entries and around transit stops. Bruce’s message for would-be “green builders” and the industrial fabrics industry is simple: landscapes can be more than aesthetic. We can learn from nature to develop green building systems and landscapes that serve as engines for the long-term health of the environment—and our own.

Frank Edgerton Martin writes frequently about design and urban landscapes.

Eberhard Zeidler strives to include community and environment in his buildings

Fabric Architecture | November 2009

By Jean M. Cook

In downtown Toronto, the tiers of offices inside the Zeidler Roberts Partnership (now called Zeidler Partnership) building overlook a small oasis. At the center of the building, sun streams into an atrium from skylights four stories above. Tall ficus trees within filter the sunlight, forming a lacy leaf roof over nearby cubicles.

Although it may be on a small scale compared to other projects the firm does, the office reflects two of the ideals held by the firm’s partner in charge of design, Eberhard H. Zeidler. These ideals are people and light—a sense of community and environment. “It makes me furious when people don’t think about people,” he exclaims. “After all, it doesn’t cost more to do that if it is designed well.”

Zeidler graduated from Bauhaus Weimar in architecture and from Technisch Hochschule Karlsruhe (now Karlsruhe Institute of Technology.) He worked in Germany a few years before emigrating to Peterborough, Ontario, in 1951. There he joined Blackwell and Craig, where he became associate in charge of design, then in 1954, a partner. The firm moved to Toronto in 1962.

Compared to the modernists who strictly followed the Bauhaus dictum of “less is more,” Zeidler has raised the roof, first with glass, as two of his best-known Toronto creations can attest. Later with fabric and combinations of fabric and glass.

Queen’s Quay Terminal is a lakeside warehouse renovated into a mixed-use building with condominiums, which overlook the lake or one of two interior parks. The parks are four stories high, glass-domed, and replete with full-size evergreens, shrubs, stone paths and benches. One includes an 8m-high waterfall and a suspension bridge 8m above the park floor. Toronto Eaton Centre in downtown is also glass-enclosed with trees and park benches along a central corridor, imitating a village street. A flock of fiberglass-sculpture geese fly above.

Zeidler’s first design job was a hospital. Since then, he has been involved in the design of more than 2,000 projects and become known for revolutionizing hospital design. And more recently, he has become a proponent of the use of fabric in architectural designs.

His breakthrough in hospital design was McMaster Health Science Centre, one of the first medical buildings to be interstitial. The idea came from office buildings in which tenants generally stay five to 10 years before moving to different quarters.

“What we really did was to say ‘What if we built [McMaster] as an office building in which each department is a tenant?’” Zeidler explains. This approach, taking into consideration the interrelationships of the departments, has resulted in changes to the building being minimal and relatively inexpensive.

“All innovation, to my mind, comes from relating two things that were previously unrelated.” Hospitals and offices, for instance. Or parks and village streets in urban buildings. Or fabric and architecture. But the truth of his statement applies outside of architecture. Zeidler points out that the scientists who are credited with discovering DNA might not have if they hadn’t spoken to a scientist in another field who referred them to additional research materials.

His reference to science is not unintentional. The premise of Bauhaus or Modern architecture was that through science and technology we could ultimately understand environment, Zeidler explains. It was expected to simply be a matter of time before that status was reached. But, he continues, what Modern architecture ignored was substance. As a result, a gap exists between architecture and an understanding of environment. “The more I meet really great scientists, that point becomes obvious,” he says.

In the 1980s, Post-Modernism addressed the emotional side of architecture. “I thought the Post-Modernists were opening the door to get away from the Modernists, but they quickly went to the other extreme—that emotionalism is everything,” Zeidler says.

And into which camp does the Zeidler Partnership fall? “I feel two things very strongly. We’re not Modernists. Nor are we Post-Modernists. To me it’s a balance between technology and emotionalism.”

These combinations of old and new, of technological and emotional, are present in many of his designs. And in the past few years, fabric has played an increasing role in some of these combinations.

Zeidler first used fabric in 1970 in an outdoor amphitheater at Ontario Place, a large urban waterfront park. But the fabric roof was later replaced with copper. “I wish we hadn’t replaced it, but the acoustics people felt the copper provided better acoustics,” he says. “Fabric can now adapt to anything you need it to in terms of heat, cleaning, sound—all issues can be resolved. But like any material, it is best for certain applications. The worst thing that can happen is to have an architect use a material without proper investigation into its applications. Then if the project fails, the material is blamed.”

At Ontario Place, a fabric roof does remain over the play area in the Children’s Village. After using fabric in that project, he included the material in “a whole bunch of designs,” including a patented retractable dome roof, but they were never made.

Things changed, however, with the construction of Canada Place and Ontario Pavilion in Vancouver, British Columbia. Both were built for the Expo ’86. Ontario Pavilion was intended as a temporary structure and has been dismantled. But Canada Place now houses the Vancouver Trade and Convention Centre, a luxury hotel and a cruise ship terminal.

The first plan of Canada Place, designed by other architects, was rejected by the city, which said it looked like a large warehouse. “I used the fabric then, not because it was cheaper—because it wasn’t—but to give it that needed uplift,” he says. “We had done all the functional things that were needed, but that hadn’t been enough. The entrance to the harbor is an important symbol.” The addition of nautical detailing and the Teflon-coated fiberglass “sails” on the top level helped create that symbol, a “ship” at the mouth of the harbor.

The completed Canada Place received a positive reaction from the public despite the fact that a number of his buildings have been controversial for their inclusion of fabric. Zeidler says his firm doesn’t intentionally create controversial designs. And he quickly points out that although receiving criticism initially, many of those buildings have since become landmarks. Canada Place bears out this claim—it has appeared on a Canadian postage stamp and graced the cover of an official tourism brochure for the province.

Canada Place isn’t the first Zeidler building to be described as a ship. “It is only when you use materials in the way they must be used that these references are made,” he says. “And that can be good.” It means the architect did enough research into the material and used it in a manner that answers the design problem and draws an emotional response as well.

Some obvious uses of fabric materials are marquees and awnings, he says, “but fabric becomes really powerful where you have large open spaces. The light plays, without the problems of glass, with which shading needs to be created. It almost gives a Mediterranean feel to a space.”

This Mediterranean feel is apparent in one of his more recent projects, Sherway Gardens. The shopping center in Etobicoke, Ontario, was renovated to include a fabric roof that incorporates three skylights. Now, as with Sherway, he is trying to combine fabric with glass in other design proposals, including one for a project in England and one for renovation of the Pearson International Airport in Toronto.

Before determining which projects are best suited to fabric use, however, Zeidler says care must be taken to consider the four conditions for architecture: function, construction, beauty and especially place—because architecture is not moveable. “We try to respond to the conditions of the place,” he says. Style can be determined historically, he explains. For example, Gothic style on each Gothic building may look different from the others.

When asked about a style in which his buildings might be categorized, he replies, “I don’t think an architect can develop a style.” While working on a project, concentrating on establishing a particular style is not the priority, Zeidler continues. Rather, he believes the priority for architects should be to strive for an integration of their buildings within a city. However, he admits, an architect’s work may be labeled a particular style in retrospect.

“Later on, people will probably say there is a certain consistency to what I’ve done, but it’s not that consistency I’m striving for. It’s a particular answer to a problem.”

And perhaps it’s just as well that he avoids categorization. “The thing that is really amazing to me,” he says, “is that people do not respond as strongly to historical designs as much as the people who design such buildings think they will.” Zeidler says he finds that “people are looking for a variety and a complexity on one hand and a certain order on the other hand. For example, there’s a geometrical order to a cloud or a mountain, but we see it as beautiful. That complex order can also occur in a beautiful city—but not a militaristic order like the Modernists saw. A taming of the complexity of the space and yet a freedom to the design—that is what I consider as exciting in architecture.”

Jean M. Cook was editor of Fabric Architecture magazine from 1990–1996. This article ran in the Winter 1990 issue, her first.

A new frontier for fabric applications begins at the Vancouver Aquarium’s new Aquaquest-Marilyn Blusson Learning Centre

Fabric Architecture | November 2009

By Frank Edgerton Martin

The Vancouver Aquarium’s new Aquaquest-Marilyn Blusson Learning Centre immerses visitors in the temperate rainforest along British Columbia’s coasts. As a certified LEED Gold project and one of the province’s most “green” public buildings, Aquaquest is also home to the first modular living wall installation in North America. The new building and its outdoor living wall evoke the sight and smells of a cliff face or canyon wall rich in plants, insects, birds and butterflies. Green design is also part of the learning message. By combining rain forest plantings and showing strategies for rainwater collection and reuse, Aquaquest’s building and landscape architecture offer a public demonstration of the promise of sustainable integrated design.

Sharp & Diamond Landscape Architecture Inc., of Vancouver, B.C., Canada, began the living wall design with what principal Randy Sharp calls a plant “wish list” of 15 possible species, including ferns, grasses, sedums, perennial wildflowers and evergreen groundcovers. Yet, because green and living walls are so susceptible to local climate extremes and site-specific conditions such as sun and wind, their plant palettes must be carefully tested. A key to success in any green wall project is to find the right fabricator and contractor who bring technical experience and a willingness to test design strategies on-site. G-Sky Inc., also of Vancouver, worked closely with Sharp to experiment with the wall fabrication and its plantings.

Sharp explains that there are two basic types of green wall systems, “Green façades are trellis systems or cable structures installed for climbing plants to grow vertically without attaching to the surface of the building.” In contrast, a living wall, as seen at Aquaquest “is part of a building envelope system where plants are actually planted and growing in a wall system.” A living wall offers the chance to plant a greater variety of nonclimbing species, yet they are also more technically challenging.

Like green roofs, successful living walls require a careful balance of trade-offs: overall weight and plant growth must be manageable while (in the case of Aquaquest) achieving a visual diversity that conveys the textures and seasons of British Columbia escarpments. For example: in testing, sword ferns and fescue grasses propagated quickly with beautiful textures, but they created excessive pressure inside the wall panels. Ultimately, Sharp & Diamond chose tough hardy native groundcovers and ferns (see planting list below). G-Sky grew the green wall panels in a greenhouse and delivered them to the site for installation in one day. Such rapid assembly is a major advantage of modular panel systems, as is ease of access the core wall and spot replacements.

Sharp & Diamond, working with G-Sky, has recently completed a new generation of living wall at the Vancouver International Airport. With documented benefits for heat islands, sound control and building energy savings, this market will continue to grow. The challenge is to develop wall systems that are more durable and cost-effective for commercial applications and prefabricated structures. “There is a huge potential for inexpensive green facades on big-box retail, industrial buildings, freeways and blank concrete walls, as well as rooftops that cannot support the weight of a green roof,” Sharp says. “By transforming urban environments with green facades and living walls, cities will become more livable, cooler and quieter.”

Frank Edgerton Martin is a contributing editor for Fabric Architecture specializing in design and urban landscapes.

Zaha Hadid’s tiny Burnham pavilion captures Chicago’s grand plans

Fabric Architecture | November 2009

By Frank Edgerton Martin

For centuries, fabric pavilions have enlivened festivals and great events. Zaha Hadid brings a 21st century update to festive structures with a salute to one of America’s greatest architects and urban visionaries—Daniel Burnham. The lead architect for the 1892 Columbian Exposition (immense but also temporary), Burnham is best known for saying “Make no small plans.” His later 1909 Plan for Chicago with its regional planning perspective and exquisite bird’s-eye views of radiating Parisian avenues was anything but small.

A century later, Hadid’s sinuous pavilion (paired with a design from UNStudio) celebrates Burnham’s grand plan at the center of Millenium Park. Together the two structures are a study in contrasts. UNStudio’s pavilion is square and constructed of laminated wood with tongue-like openings that frame outward views of the great skyscrapers lining the park. Hadid’s tension-fabric pavilion is inward-looking, luminescent, and lightweight in feel — almost as though it were a floating cloud brought down to earth.

Sited along one of the great proposed diagonal avenues of Burnham’s plan, the pavilion’s aluminum structure metaphorically evokes a radiating pattern of city streets and boulevards. Tightly zipped around the frame, 24 fabric panels serve as an interior screen for a video installation by London artist Thomas Gray that explores Chicago’s past and future. Projected from one end of the interior and from a third source between the interior and exterior skin, Gray’s changing images recall the “urban fabric” of Chicago’s neighborhoods and the hopes of citizens today for the region’s next century.

If you watch the Pavilion’s time-lapse assembly video (see references below), the rapid installation seems well-rehearsed. Yet, this custom project proved anything but simple to install and suffered from repeated delays. With its long-term knowledge of fabric and structural technologies, Chicago’s Fabric Images Inc. came to the rescue as the second installation contractor.

An architecture graduate of the University of Illinois, Fabric Images’ Gordon Hill worked to coordinate the assembly of the structure’s 7,000 aluminum pieces and the efforts of Fabric Images’ top seamstresses who worked on-site in 12-hour shifts around the clock to ensure an opening by mid-summer. Working with an engineer, Fabric Images re-engineered the supporting trusses. “The ideal approach would be to take it back to the shop to rebuild it,” Hill says. But given that they needed to compress six months of work into 30 days, the company moved its entire crew onsite. “It was meeting Hadid’s architects on-site and asking them about their design intent that made all the difference,” Hill says. Each day he worked like a “short-order cook” to make detail sketches to solve immediate problems. “The focus was not on how we wanted to do it, but Hadid’s vision.” Working in public view, they opened the Pavilion by the end of July.

Zaha Hadid is emerging as a leading designer in temporary fabric architecture for everything from London’s Serpentine Pavilion to music festivals. Her Burnham project is remarkable as it captures Chicago’s great historical events and stories in such a small organic space. “Fabric is both a traditional and a high-tech material whose form is directly related to the forces applied to it — creating beautiful geometries that are never arbitrary,” she explains. “I find this very exciting.”

Frank Edgerton Martin is a contributing editor for Fabric Architecture specializing in design and urban landscapes.