Revolutionary Tensioned-Membrane Structures  

Fast tracking, value engineering, sustainability, and integrative design are driving the delivery of most 21^st century buildings. These initiatives are supported and encouraged by architects and owners racing toward ever-tightening project-delivery schedules, budgets, and energy-efficient mandates.

It takes a remarkable structure to meet the goals of a remarkable company. When constructing its headquarters in Kent, Washington, Blue Origin opted for a solution that incorporates energy efficiency, sustainability, and speed: a tensioned-membrane aluminum-supported structure.

Photo courtesy of Sprung Structures, Inc.

Design teams often confront owners with a “devil’s bargain.” All too frequently, there is a trade-off between two of three choices: cost, schedule, or quality. Design and technological advances in tensioned-membrane aluminum-frame-supported structures may provide an alternative for owners and architects who want it all. TESLA to SpaceX, Harvard to Blue Origin, data centers to ice arenas, clients are choosing to fast-forward into the 21^st century with sustainable buildings that deliver on cost, quality, and schedule without sacrificing permanence and beauty.

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Photo courtesy of Sprung Structures, Inc. 

A high-performance tensioned-membrane aluminum-frame-supported structure is eco-friendly, and components exceed building codes and some of the most stringent green rating system criteria. These structures provide the same functionality as a traditional building type, but at a much lower cost and with a much faster construction time. The tensioned-membrane exterior, the blanket insulation, and the interior liner, provides an insulated, virtually airtight barrier for protection in any climate. The interior membrane is the interior wall surface and requires no additional drywall, plaster, painting, or resurfacing, as it is part of a complete building package. 

Many design professionals are not aware of this alternate type of building, particularly as a permanent building system rather than a temporary alternative. According to Sprung Structures Vice President Jim Avery, “One of the most common misconceptions is that tensioned-membrane aluminum-frame-supported structures are tents and can only serve as a temporary construction solution. Quality starts with the intelligent design of these buildings. Considering the rapid construction time, superior energy efficiency, long-term flexibility, and lower overall costs, tensioned-membrane aluminum-frame-supported structures perform as well or better than other traditional building types.”

The following guidelines and case studies will provide more detail as to how to select tensioned-membrane aluminum-frame-supported structures as a permanent solution to complex programming requirements. From visioning and programming to post-occupancy, design professionals are finding these structures an unconventional solution for new 21^st century problems.

Project Management

According to the American Institute of Architects (AIA), project management is vital for the success of every project. As with any project, the selection of a pre-engineered building such as a tensioned-membrane aluminum-frame-supported structure requires careful planning. The architect articulates client goals, creates a vision, and analyzes planning and code requirements before developing construction documents. Any successful project begins by listening and developing strong communications between all members of the team. A tensioned-membrane aluminum-frame-supported structure is engineered from the baseplate forward, which means incorporating the manufacturer as a key team player. Foundations, whether the structure is built on concrete or anchored to grade with earth anchors, must also be considered in the overall design.

This building type is similar to that of a modular construction system. According to the AIA, “An increasing number of building projects across several markets are using modular construction, the process by which components of a building are prefabricated off-site in a controlled setting and then shipped to the project site and assembled. This approach allows projects to capture the efficiencies gained by integrating the processes and technologies of design, manufacturing, and construction—without having to compromise on aesthetic intent. According to research conducted by McGraw-Hill Construction, when implemented effectively, this approach has been shown to result in a higher-quality building, delivered in a shorter time frame, with more predictable costs and fewer environmental impacts—for example, through reduced material use and waste.”¹

Aesthetically, design modifications can include changes in shape, color, building orientation, entry components, daylight strategies, and interiors. All of these are driven by the architect’s vision. Early discussions with municipal planners will pave the way for those communities unfamiliar with the permanence of these structures. One of the key differences in the project delivery of these structures is how quickly they can be assembled. The rapid construction of a revolutionary manufacturing plant in 19 days is a demonstration of how quickly a building can be raised. Coordination of the building envelope with machinery, equipment, and even elaborate interiors is key to successful project delivery.

Blue Origin and New Life Christian Academy, highlighted later in this course, are examples of buildings with multistory mezzanine interiors. By code, a membrane structure, no matter how tall, is classified as a single-story structure. Other examples that follow demonstrate projects that are reused over a period of 25 years in three different locations and for homeless navigation centers. Some of these projects are located on existing parking lots, while others are on more traditional foundations. They are designed to adapt to all climate challenges. In all of the following examples, the tensioned-membrane aluminum-frame-supported structure provides numerous economic and environmental advantages while exceeding client expectations.

The City of Phoenix's homeless navigation center offers an array of on-site support services for vulnerable men and women in need of assistance.

Photos courtesy of Sprung Structures, Inc.

The City of Phoenix's homeless navigation center houses a total of 200 beds.

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Mission Complete at Blue Origin

It takes a remarkable structure to meet the goals of a remarkable company. When looking to construct its headquarters in Kent, Washington, Blue Origin explored conventional building options but could not wait the estimated two to three years it would take for the structure to be completed. Realizing a traditional construction route was not going to meet the company’s needs, Blue Origin opted for a much faster solution that incorporates energy efficiency, sustainability, and the highest of quality: a tensioned-membrane aluminum-supported structure by Sprung.

Built in just 11 months, this high-tech, 222,700-square-foot facility is visually striking both inside and out, with vibrant colors, acoustically insulated partition walls, and seemingly endless amounts of space for employees to work, gather and collaborate. Featuring ample natural light and amenities that include a garden, fitness facilities, an auditorium and more than 100 conference rooms of varying sizes, the structure was completed on time and on budget, and it now serves as an ideal setting for inspiration and innovation. At a time that requires the reimagining of the construction industry around the world, delivery of a faster, more flexible, cost-effective building solution that can adapt to changing needs and emerging markets is more important than ever before.

Photo courtesy of Sprung Structures, Inc.

Photo courtesy of Sprung Structures, Inc.

The 270,000-square foot head office for Blue Origin in Kent, Washington, erected from ground breaking to completion in just eleven months.

RAPID EVOLUTION AT TESLA

Constructed in 19 days, the general assembly line in this tensioned-membrane aluminum-frame-supported structure produces up to 5,000 TESLA Model 3 cars per week.

“We believe in rapid evolution,” stated innovator, engineer, futurist, and TESLA founder Elon Musk in an interview with The New York Times. “It’s like, find a way or make a way. If conventional thinking makes your mission impossible, then unconventional thinking is necessary.”²

Photo: Justin Kaneps for The New York Times

TESLA Model 3 assembly line was constructed in 19 days.

In order to meet aggressive manufacturing goals, Musk selected a new type of structure to house a general assembly line. TESLA required a strong, conditioned building with clear spans and a high ceiling. The building needed to meet all of the mechanical, electrical, and fire-safety requirements of a manufacturing plant. The immediate demand for more of the world’s greenest cars required that this building meet occupant standards for the grueling 24/7 assembly line schedule as well as green building environmental goals. The production of the new Model 3 TESLA was behind schedule, and a new conventional building was impossible.

The unconventional solution chosen by Musk is a membrane-supported aluminum-frame building. Erected in 19 days on a parking lot in Fremont, California, the building is a reflection of TESLA's aim to create products that are both revolutionary and environmentally friendly. “No standard automotive solution could be built in time,” Musk said, “so we created a new solution. It is working and has slightly higher quality than the more traditional general assembly line. Perhaps most surprising is that the total cost of production…is lower.”

This massive manufacturing plant is 915 feet long, 150 feet wide, and 53 feet tall. The frame provides a clear-span interior of 137,250 square feet—large enough to fit two and a half football fields. Within three weeks, the building was completed; the production line was built in tandem with the frame, which was assembled and erected along with the membrane cover in stages. The construction team was running three shifts to keep up with TESLA’s techs as they built the assembly line underneath the frame as each section was finished. No concrete foundations were poured. This structure was anchored entirely to the existing asphalt parking lot using earth anchors.

Photo: Justin Kaneps for The New York Times

This massive manufacturing plant is 915 feet long, 150 feet wide, and 53 feet tall. The frame provides a clear-span interior of 137,250 square feet—enough to fit two and a half football fields.

“This whole thing that you see here was a pretty miraculous effort by the team to create a general assembly line out of nothing in three weeks. It was life or death,” said Musk during a CBS 60 Minutes interview: “Those betting against the company were right by all conventional standards that we would fail. But they just did not count on this unconventional situation of creating an assembly line in a parking lot in a tent.”³

Although Musk referred to this building as a tent, in reality, this revolutionary structure is derived from the same technology as the Conestoga wagons that brought earlier pioneers West. A Conestoga wagon was a tensioned-membrane supported structure on a moving wagon. The sturdy fabric, supple wood frames and support system allowed the settlers to meet the challenges of a long journey through deserts and mountains.

The energy and atmosphere in TESLA's new, light-filled, energy-efficient manufacturing facility supports the future-forward aspects of the company. The general assembly line produces up to 5,000 TESLA Model 3 cars per week, increasing production output by 50 percent in a matter of three weeks. The strength, stability, and high performance engineered into the TESLA assembly line are a demonstration of the evolution of tensioned-membrane aluminum-frame-supported structures as permanent buildings.

Performance Standards: Analyzing Code Compliance

Engineered tensioned-membrane structures have several components. Modular, vaulted frames are assembled as a system braced by intermediary members. The materials that comprise these systems include bolted aluminum frames, architectural coated interior and exterior membranes, and optional formaldehyde-free insulation packages, skylights, and window and door systems.

As with more conventional modular systems, when selecting a tensioned-membrane aluminum-frame-supported structure, the design professional is required to make more decisions at earlier stages in the project. Communication between the design team, the owner, the manufacturers, and the foundation, mechanical and electrical engineers, as well as the contractor and manufacturer’s technicians is critical to the success of the project. The professional armed with certifications of code compliance to strict energy, structural, fire-safety, and occupancy requirements will ease the path to planning and building department approvals. The International Building Code (IBC) includes the following definitions to describe tensioned-membrane aluminum-frame-supported structures:

• A membrane-covered frame structure is defined in the International Building Code (IBC) in Chapter 2: Definitions as a “non-pressurized building wherein the structure is composed of a rigid framework to support a tensioned membrane which provides the weather barrier.”
• Membrane structures are addressed in Chapter 31, Section 3101. Section 3102.1: General states: “The provisions of Sections 3102.1 through 3102.8 shall apply to air-supported, air-inflated, membrane-covered cable and membrane-covered frame structures, collectively known as membrane structures, erected for a period of 180 days or longer. Those erected for a shorter period of time shall comply with the current International Fire Code.”
• The type of construction for membrane structures is defined in Section 3102. They can either be defined as Type IIB or Type V construction. The code states: "Noncombustible frame or cable-supported structures covered by an approved membrane in accordance with Section 3102.3.1 shall be classified as Type II B construction…Other membrane structures shall be classified as Type V construction.”
• The membrane portion of the structure is to be designed as per the ASCE Standard 55: Tensile Membrane Structures, which states, “This standard provides minimum criteria for the analysis, design, and performance of membrane-covered cable and rigid member structures, collectively known as tensile membrane structures, including permanent and temporary structures…The requirements of this standard shall apply whether the tensile membrane structure is independent of or attached to another structure.”

The code does not restrict the use of this structure to temporary installations. As long as the assembly meets code requirements, these structures can last as long as traditional building systems. Along with the codes that define membranes, the other key areas to consider are the supporting aluminum structure and necessary fire-code requirements.

The community recreation center for the Town of Mammoth Lakes is a year-round indoor recreational facility.

Photo courtesy of Christian Ponella

LA Kings Ice, at Mammoth Lakes, features an Olympic-sized ice rink.

Lightweight Aluminum Frames

The code is specific regarding the aluminum frames. Lightweight aluminum frames provide numerous advantages when used in buildings. Aluminum is recyclable and can be selected with a high content of recycled materials. The use of aluminum in construction allows for the easy and efficient assembly of components. 

Assembly begins with the delivery of premanufactured, engineered aluminum frames. These frames are placed on-site in well-marked pieces, arranged in order of assembly. Assembled in place, the frames are hoisted into space and secured to the appropriate foundation. After a review of the structural loading of the building, as well as an analysis of soil conditions, an engineer may select an earth anchor as an alternative to a traditional foundation. 

The lightness of the aluminum frame and membrane building skin contribute to the equation that helps the engineer determine where earth anchors can be used instead of concrete footings, which allows these structures to be built on existing parking lots. Earth anchors are devices that are engineered for use both in temporary and permanent applications.

Image courtesy of Sprung Structures, Inc.

 

These aluminum-frame-supported structures can meet the requirements of Section 507 of the IBC, Unlimited Area Buildings. Structures can be set back accordingly, and sprinkler systems can be installed. Chapter 20, Section 2002 of the IBC does allow for aluminum to be an acceptable structural building material.

The large structural aluminum frames are designed to support the weight of the overall structure in conjunction with utility or equipment loads, as well as wind and snow loads. This type of building can be engineered to meet even the most stringent hurricane loading conditions. Depending on configuration, the wall and roof sections of these structures have been tested and meet Miami Dade NOA requirements.

After the frame is erected, an exterior membrane is winched into place between the frames, then tensioned with a 10-ton hydraulic jack and ram to 20 pli in the horizontal direction. This provides the exterior skin for the building. Electrical and mechanical systems are placed in the frame, along with an extensive network of accessible power requirements and ventilation systems that maximize flexibility for future equipment modifications.

An interior membrane is winched into the frame. This membrane can be insulated and provides the finished surface of the interior. Mechanical and electrical access panels are placed along the interior walls. Skylights, doors, windows, and transparent panels enclose the finished structure. Attachments such as mechanical systems, sprinklers, lighting, and heavier equipment are engineered into the structure using direct connections to the bottom flange of the beams, and are reviewed on a case-by-case basis. Hanging brackets are available from the structure manufacturer and can be rated to meet the requirements of NFPA 13.

In IBC Chapter 20, Section 2002: Materials, the use of aluminum is allowable for structural materials. The Aluminum Association’s Aluminum Design Manual 1 (ADM1), Chapter 35, references Part 1-A: Specification for Aluminum Structures, Allowable Stress Design and Part 1-B: Aluminum Structures, Load and Resistance Factor Design (1604.3.5, 2002.1). Structures are to be designed using the minimum load requirements as referenced in Chapter 16 using accepted engineering practices.

Aluminum is durable, lightweight, long lasting, and one of the most recycled metal products in today’s market. In addition, aluminum frames are easy to mount into place. Connections are fitted and bolted rather than welded (as is typical in a steel superstructure), which means the frames can also be easily demounted and reused. The structural system is engineered to withstand high wind loads and shed snow. The aluminum framework is 100 percent recyclable, with no loss of quality when reused in another product.

THREE LIVES FOR ONE BUILDING

Photos courtesy of Sprung Structures, Inc.

Canyons Ski Resort Arena at Wolf Mountain Rollerblade Rink, 1994–1997.

Photos courtesy of Sprung Structures, Inc.

City of South Jordan Public Works Vehicle Maintenance, 1998–2008.

Photos courtesy of Sprung Structures, Inc.

Jordan School District Bus Maintenance Facility, 2009–present.

The long-term value and recyclability of a tensioned-membrane aluminum-frame-supported structure is demonstrated by the construction, deconstruction, and reinstallation of an 88-foot by 230-foot enclosure in Utah. In 1994, Wolf Mountain, now Canyons Ski Resort, utilized this non-insulated colorful building for concerts and roller hockey. Amid preparations for the upcoming Salt Lake City 2002 Winter Olympics, the structure was moved to make room for the new infrastructure that was necessary for the resort to play host to various Olympic events.

One Structure 3 Lives

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Reuse vs. Recycle

Rather than recycle the materials, the City of South Jordan purchased the building for reuse. The structure was dismantled and shipped back to the original manufacturing plant to be reworked, cleaned, and supplemented with additional doors and windows. In 1998, the structure was then re-erected on City property as a vehicle maintenance and training facility, where it remained until November 2008. The structure allowed the City to increase space immediately while appropriate funds could be raised to complete its new $10-million Public Works headquarters. After the new building was finished, the City sold the structure to the Jordan School District in October 2008.

As the third owner, the Jordan School District had the facility dismantled and stored for the remainder of the winter. In 2009, it purchased a new sand-colored exterior membrane complete with a terra-cotta wainscot and a partial replacement insulation package. The structure was then re-erected as a bus maintenance facility in West Jordan, Utah. Air-conditioned offices were built into the structure, and new doors and canopies gave the facility a fresh look.

Thirty-two years after its initial purchase, this facility continues to provide value to its owners. The aluminum frame and some of the original membrane were recycled. 

Aluminum is highly recyclable, containing up to 80% post-industrial scrap. At the end of its life cycle, aluminum can be recycled at a rate of 90-95%, ensuring minimal waste. Upwards of 60% of aluminum in North America is produced using hydroelectric-powered smelters, which have a much lower environmental impact, reducing the carbon footprint.

Additionally, aluminum’s corrosion-resistant properties contribute to the longevity of the structure, reducing the need for replacements and repairs. The lightweight nature of the substructure further minimizes transportation emissions, making Sprung an environmentally responsible choice for modern construction. Favorable environmental product declarations (EPD) are available.

Fire Code Advantages

The approved membrane to which Section 3102.3.1 is referring must “meet the fire propagation performance criteria of NFPA 701 and the manufacture’s test protocol.” Typically, architectural membranes that are used as membrane structures would need to comply with NFPA 701, ASTM E-84, California State Fire Marshall, and the Canadian standards CAN/ULC-S-109 and CAN/ULC-S-102 fire-test standards in order to meet the intent of the building code.

Typically, the architectural membrane is considered non-rated and the aluminum supporting framework can be considered noncombustible. This would define this structure configuration as Type IIB construction. Type IIB construction is the most common type of construction used in building materials. In conjunction with the membrane, and as per testing on behalf of the American Aluminum Association, 6,000 series aluminum also meets the noncombustibility requirements of ASTM E-136. Therefore, Type IIB construction for tensioned-membrane aluminum-frame-supported structures is applicable.

Tensioned-membrane aluminum-frame-supported structures are a complete building system. The interior is the finished wall system. Depending on the use and occupancy classification, the membrane acts as the interior finish and will need to meet the requirements of Section 803.1. Membranes can be specified with a Class A rating as per the testing requirements of ASTM E-84 with a flame spread index of 25 or less and a smoke developed index of 450 or less. The membrane manufacturers need to provide the necessary documentation to ensure that the membrane meets the requirements of the building code.

Based on experience with this type of structure, and as attested to in the commentary section Appendix CA of ASCE 55, membrane structures can be considered as safe or safer than conventional structures for the following reasons:

• An internal fire source may generate sufficient heat to damage the architectural membrane, which allows for the venting of smoke and heat.
• High-vaulted ceilings create a smoke reservoir in the roof area, leaving the floor clear of smoke. This makes it easier for the public to safely exit the structure and for fire fighters to locate and extinguish the fire. This also provides early heat and smoke venting, reducing the risk of flashover.
• Roof monitors with dampers can be installed to remove smoke as it collects in high roof (smoke reservoir) areas.
• Conventional sprinkler and fire alarm systems can be installed into membrane structures. Low-heat sprinkler heads are also available for these structures.
• Exit doors are easily installed and integrated into membrane structures as required.

Although first-generation tensioned-membrane aluminum-frame-supported structures tend to be one-story clear-span buildings, new projects include those with interior partitions, and some include mezzanines, which can occupy one-third of the structure area. When designing a path of travel, emergency exits with panic hardware can be installed into the membrane structure as well as into interior partitions. Exit distances and widths can be adjusted based on occupancy.

Mesa Gateway Airport provides a comfortable environment for passengers.

Photos courtesy of Sprung Structures, Inc.

Performance Architectural Membrane

The architectural membrane of a tensioned-membrane structure provides the exterior wall, the roof, and the finished interior surface of the building. Architectural membranes weigh from 18 to 24 ounces per square yard, making them one of the lightest finish building envelope materials available to a design professional. All-weather outer membranes are delivered on-site in rolls and winched along the frame from one side to the other using spacer bars, similar to the lofting of a sail.

The membrane panels are tensioned across a spreader bar in the frame, and insulation is added to the ribs, as well as an interior membrane, and tensioned into place by hydraulic machinery. The manufacturer supplies contractors with training and assistance in handling the unique interior and exterior finish materials that are part of the structural system. 

Jobsite quality standards for handling membranes to avoid scratches or blemishes on interior walls and ceilings should be developed and monitored during construction. The membranes have a selection of protective coatings available, from acrylics and polyurethanes with 15- to 20-year life expectancies utilizing PVDF, Tedlar, and Kyner with 20- to 30-year life expectancies.

Membranes can have translucent surfaces to allow for additional daylight. Membranes can also be fitted with door and wall sections. The top sections of both the exterior and interior surface of the membranes are designed to allow for optional skylights along the apex of the spine of the building. These provide an abundance of natural light for high-ceiling structures.

Photo courtesy of Sprung Structures, Inc.

Diagram example of architectural fabric membrane composition.

A fabric is defined as a two-dimensional cloth made up of yarns, or slit tapes that may be impregnated with a matrix that binds them together. The yarns, which can be woven or laid, are frequently coated or laminated. A membrane is defined as the flexible, coated, or laminated structural fabric that supports imposed loads and transmits them to the supporting structure. 

The membranes in a tensioned-membrane structure carry only tension or shear loads in the wrap and fill directions of the membrane. Due to the ductility of the aluminum-supporting framework, tension-membrane structures are engineered to have some movement in the frames.

Because the membrane is fed through the extruded channels in the aluminum I-beam, there are no wear points. When it is time to replace the membrane, sections can be replaced in segments without exposing any interior furnishings or fixtures. 

These surfaces can be specified with a protective film coating that will guard against ultraviolet rays as well as airborne contaminants. A durable, colorfast membrane can be provided with a warranty for 25 years. Membranes can be specified with a solid color or printed with an unlimited selection of patterns, logos, photos, and symbols. They can be selected in multiple colors to match existing surfaces.

COLOR AND SUSTAINABILITY AT HARVARD

In order to build its new business school, the Ruth Mulan Chu Chao Center, Harvard University had to tear down its 1950-built Kresge Hall, which contained executive dining facilities. The university chose to build a tensioned-membrane aluminum-frame-supported structure as an interim dining and kitchen facility—an unconventional solution that met key aesthetic, budgetary, and strict timeline objectives. A prime factor in Harvard’s decision to go with a membrane structure was color—specifically, the fact that the membrane exterior could be color matched to the exterior of the existing architecture at Harvard. 

This facility is a tensioned-membrane structure that is made up of a series of aluminum frames covered with a polyvinyl chloride (PVC) membrane stretched between them. The structure utilizes a number of extruded 5-by-10-inch aluminum I-beams to span the 80-foot width. It is installed as a permanent facility (though designed to be relocated) and will be on-site for up to 32 months. Full HVAC facilities are incorporated to keep occupants cool in summer and warm during the winter months. This works very efficiently thanks to the 8-inch-thick (R-25) blanket of fiberglass insulation within the walls of the structure.

The design team from Shepley Bulfinch delivered high-end finishes, solving multiple space issues. It added acoustic ceiling clouds with drop pendants, as well as dramatic daylight panels in the center of the dining area. The team also addressed space and volume by creating viable transitions between the seating area and the kitchen. The food service production facilities include cooking modules, prep stations, cold and dry storage, and a 24-hour bakery. There are staff locker rooms and a series of enclosed modular walkways that ease the transition between task areas. Harvard chose quality, speed, and sustainability with a frame-supported, architectural membrane-clad modular food service complex fit within a grove of protected trees.

Harvard Business School seats 400 and serves meals 3 times daily.

Photos courtesy of Sprung Structures, Inc.

 

Harvard Business School interim dining.

A Complete Building Enclosure

When the engineering of the building’s climate protection is delivered as a complete wall system, the skin of the building contains the thermal insulation plus air and vapor barriers, providing excellent thermal performance. Air permeability is close to zero in these buildings. Insulated floor surfaces are completed in a similar manner to that of a traditional slab-on-grade building. All building systems that penetrate the exterior are achieved using framed penetrations or frameless penetration kits.

Architectural membranes can be selected with high-performance insulation to meet arctic climates. These high-strength rip-stop membranes are fire-resistant and durable. A blackout layer can be specified to prevent solar gain and manage climate control, and a daylight membrane can be specified to provide an abundance of natural light, reducing lighting costs.

Examples of the climate adaptability of these structures include those that are installed at the North Pole and South Pole, as well as those used by the U.S. Military in the Kuwait desert. The Missile Defense System utilized a membrane structure located in Shemya Island, Alaska, which is engineered to withstand wind loads of 120 miles per hour. The Warwick Le Lagon Resort & Spa in Vanuatu, in the South Pacific, was used as a storm shelter on March 13, 2015, during Cyclone Pam, a Category 5 cyclone. Due to its ductility, this structure also withstood a 7.3 Mw earthquake in December 2024. The facility at Kirkwood Mountain Resort in Lake Tahoe performed perfectly during a period of record snowfall of almost 10 feet by continuously shedding the snow off its roof. These are among the many examples of the strength of the membranes supported on aluminum frames. Many structures have been erected in the hurricane-prone Gulf states, and have been designed to meet wind speeds of up to 180 mph.

Image courtesy of Sprung Structures, Inc.

Shown is a layer of formaldehyde-free fiberglass blanketing that’s up to nine inches thick for our insulated structures. This allows for a standard building envelope with insulation values ranging from R-25 to R-47, depending on sizes, configurations, and accessories (higher values can be achieved upon request).

Energy Ratings: High-Performance Insulation

Insulation provides comfort in both hot and cold climates. It reduces the cost of climate control and absorbs sound for better acoustics. A comprehensive insulation package for a tensioned-membrane structure includes vapor barriers, thermal breaks, and a tensioned, finished interior liner. Additionally, membranes are designed to have low air and vapor permeance.

Independent blower testing conducted by the Southern Alberta Institute of Technology (SAIT) shows that, depending on configuration, membrane structures are four to five times more airtight than the values required by the building code.

Photo courtesy of Sprung Structures, Inc.

Frames are designed to accept a “sandwich” of fiberglass batting and are part of the membrane system. In any building, holes in the insulation can dramatically reduce its performance, and multiple layers of insulation may merely add to dead air spaces between each layer, negating much of the insulation value. An engineered insulation system remains in place and does not slide down the roof and bunch at the base of the wall. The specified R-value is uniformly maintained, as there are no pinch or bunching points from floor to ceiling throughout a membrane system.

Formaldehyde-free fiberglass insulation is available as part of a complete insulated building package and assists with meeting green rating system goals. Formaldehyde is a colorless, flammable gas at room temperature and has a strong odor. It can be found in numerous building products. According to the Environmental Protection Agency, exposure to formaldehyde may cause adverse health effects, from mild allergic reactions to more serious neurological conditions. 

An insulated membrane system can be specified as part of the membrane system in up to a nine-inch thickness (R-30). R-values are a measure of thermal resistance. In a membrane system, an R-30 system is both the roof and the walls, and the system can be designed to meet climate standards from -60 degrees Fahrenheit (-51 degrees Celsius) to 122 degrees Fahrenheit (50 degrees Celsius). Depending on beam size this factor can be increased to R-40 by using a dual layer insulation system.

Fiberglass insulation can be specified with third-party certifications to have a minimum recycled content of 25 percent, comprised of 20 percent post-consumer bottle glass and 5 percent post-industrial glass. Innovative insulation systems have already been developed to improve the overall R-value of the roof of the structure (above R-30) to meet some of the new energy codes.

Depending on the climate zone and the adopted energy code where the structure is to be erected, a performance path for thermal performance may be required. This takes the following into consideration: insulated concrete slab, energy-efficient HVAC equipment, energy-efficient doors and windows, renewable energy sources, natural lighting, and the airtightness of the building envelope.

Many designers use Comcheck to determine energy code modeling. Frame-covered aluminum structures are considered as metal buildings for energy code purposes and require the U factor method for compliance with both the roof and walls. 

Increased thermal values can also be achieved with the addition of an insulated thermal break on the bottom flange of the aluminum I-beam.

Image courtesy of Sprung Structures, Inc.

A 20-year life-cycle analysis of a tensioned-membrane aluminum-frame-supported hockey rink at Shawnigan Lake School in Canada provides some startling statistics. The full-size rink features an ultra-high-efficiency refrigeration system designed to dehumidify the ice arena, heat the domestic hot water, and heat the arena offices, arena, and lobby. The refrigerant was designated to have no negative effects on the environment, in line with the Montreal Protocol. 

After the structure's completion in January 2015, actual energy data and energy bills were collected and compared with the average Canadian ice arena using a comprehensive Natural Resource Canada report. The results show that the structure will save Shawnigan Lake School more than $850,000 in future energy costs. These energy savings considered the base electrical charge, power factor, and demand charge of the school.

Comparisons with Traditional Construction

In addition to favorable comparisons on energy savings, there are numerous other ways that tensioned-membrane aluminum-frame-supported structures stack up to other building types. When comparing oranges to oranges, this chart shows a few key advantages of tensioned-membrane aluminum-frame-supported structures.

Occupant Well–Being

The following two examples highlight the benefits to occupants of tensioned-membrane aluminum-frame-supported structures. The first is one of many churches that have adapted these buildings as worship facilities. The second is a corporate office that pushes design and maximizes the use of natural daylight to create a state-of-the-art open office facility.

The pastor of New Life Christian Center in Turlock, California, reports that the “facility is state-of-the-art, half the cost of traditional construction, and three times faster to build.”

Photos courtesy of Sprung Structures, Inc.

New Life Christian Center provides more than 31,000 square feet on the first floor and more than 8,000 square feet of mezzanine space.

Ministry, Not Mortgages

Dr. Brett C. Avery, former executive pastor at New Life Christian Center in Turlock, California, is enthusiastic about the tensioned-membrane aluminum-frame-supported structure chosen for his ministry. This is an “innovative, highly creative, kingdom-focused building. The team gave us a permanent facility that exceeded our expectations and allowed us to invest in ministry, not mortgages,” he says.

After evaluating the cost of a new structure for a growing congregation, the pastor chose an unusual alternative. This 150-foot-wide by 212-foot-long building includes an open-concept foyer—with daylight panels—that serves as a gathering area.

The facility is comprised of a three-story mezzanine core. This core includes a state-of-the-art worship center with seating for 1,000 people, a cafe, an expansive lobby, and a kid’s space. The facility provides more than 31,000 square feet on the first floor and more than 8,000 square feet of mezzanine space. The third floor provides space for the mechanical systems. The core of the building is constructed of traditional building materials, and the mezzanine is designed to allow parishioners to overlook the meeting areas and sanctuary.

The high-ceilinged daylit space provides access to a break area and meeting rooms, and it leads into the sanctuary. The sanctuary seats almost 1,100 people and houses a large platform stage, a prayer room, an usher’s room, and a nursing room with a view to the sanctuary. The long-term cost of ownership was a major consideration for this congregation. The insulation factor and eco-friendly construction provided both a lower dollar per square foot initial investment and significant savings in heating and cooling in the hot, dry climate of the Central Valley in California.

Photo courtesy of Sprung Structures, Inc.

This 150,000-square-foot fully insulated tensioned-membrane aluminum-frame-supported structure is equipped with two manufacturing wings and office space, and meets the stringent environmental and occupational goals.

View of the Rockies

Completed in 2007, one of the factories of this membrane manufacturer is located on 100 acres in Alberta, Canada. This 150,000-square-foot tensioned-membrane aluminum-frame-supported structure includes two manufacturing wings and office space. The building is fully insulated with R-30 formaldehyde-free insulation. Translucent panels are set into the peak of the architectural membrane.

The center core of the facility includes a 30-foot-high glazing wall that provides breathtaking views of the Rocky Mountains. The facility includes a restaurant, gymnasium, indoor gardens, lounge, athletic center, and corporate offices. The two wings of the structure house state-of-the-art manufacturing facilities for aluminum and membrane fabrication. The open plan of this office complex provides views through the building. Most employees have direct access to natural daylight, and high translucent skylights provide additional natural light. This facility feels as though one is working in a large botanical conservatory with high-end atmospheric and environmental controls.

The building is open and welcoming. An arcade of aluminum arches that surrounds the membrane allows for large windows. The mezzanine core of the building provides additional offices, meeting rooms, and balconies that overlook the gardens and first-floor offices and lobbies. The campus also includes a new greenhouse that grows produce 365 days a year for employees and local restaurants. The temperatures in Alberta, Canada, can range from 35 degrees Celsius (95 degrees Fahrenheit) in the summer to a frigid -40 degrees Celsius (-40 degrees Fahrenheit) in winter. The buildings on campus are energy efficient and meet high-performance standards as well as environmental standards for the comfort of its occupants.

Photo courtesy of Sprung Structures, Inc.

Shown is the garden interior of the membrane manufacturer’s headquarters.

Aesthetic Revolution

Tensioned-membrane aluminum-frame-supported structures are part of a 21^st century aesthetic and engineering revolution. There are many designers challenging the norms of construction and working with engineers to find new sustainable solutions to modern-day problems. Breakthroughs in prefabrication, material science, and engineering are creating new building types with high-performance energy ratings.

The uses range from high-end office buildings to manufacturing. Portable, affordable, and permanent membrane structures are being used to support disaster assistance and homeless shelters throughout the world. As Elon Musk discovered, tensioned-membrane aluminum-frame-supported structures can provide the same functions as traditional buildings at a lower cost and faster construction time.

Photo courtesy of Sprung Structures, Inc.

In addition, a wide range of accessories such as connecting corridors, glazing walls, canopies and vestibules are available to enhance building designs.

Accessories

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These buildings provide expansive natural light, both as part of a window or skylight system but also by providing an overall translucent light throughout the structure that maximizes occupant well-being. They provide a superior building enclosure that’s airtight and energy efficient. They are modular and can be deconstructed for relocation. They can provide large, open clear-span spaces used in facilities such as pools, gymnasiums, hockey rinks, aviation sheds, and even manufacturing plants. A structure up to 160 feet wide where appropriate soil conditions exist can be built on an existing parking lot. They are affordable and can be leased or purchased.

Membrane-supported aluminum structures are a sustainable alternative to traditional construction for the future. As Musk points out while discussing the new TESLA plant: “If conventional thinking makes your mission impossible, then unconventional thinking is necessary.”

End Notes

¹Design for Modular Construction: Modular Construction. National Institute of Building Sciences. The American Institute of Architects. Web. 2 April 2019.

²Boudette, Neal E. “Inside Tesla’s Audacious Push to Reinvent the Way Cars Are Made.” The New York Times. 30 June 2018. Web. 2 April 2019.

³Lesley Stahl. Tesla CEO Elon Musk: The 60 Minutes Interview. CBS News. 9 Dec. 2018. Web. 2 April 2019.