Project DescriptionBC Place in Vancouver, Canada has been transformed into a year-round, open-air facility with an innovative retractable roof featuring SEFAR® Architecture’s TENARA® Architectural Fabric. The renovated facility is once again an iconic architectural landmark for the province.
The most prominent element of the new stadium roof is the inner, retractable TENARA Fabric roof that extends from the center of the stadium where it’s hidden inside of a pod above the videoboard to a fixed outer roof. The opening is 109 yards by 93 yards; the same size as the field below and takes about 20 minutes to open or close.
The retractable roof consists of pneumatically-stabilized membrane cushions constructed from two layers of TENARA Fabric. The bleachers have been modernized and the air-dome roof replaced with 36 permanently inflated cushions of double-skinned TENARA Fabric. Only this fabric has the required translucency and foldability for this innovative design.
The TENARA Fabric cushions are prestressed using hydraulic tensioning units and inflated with fan units. The retractable roof is suspended from steel cables spanning between 6 steel masts that are 164-feet-tall by specially-designed sliding and driving carriages. The deflated cushions are stored until it is time to close the roof and the driving carriages pull the TENARA Fabric outwards radically towards the perimeter. To open, first the cushions are deflated and then winches draw the TENARA Fabric inward from all sides, enclosing it in a pod. To close, the process is reversed, and in the winter the retractable roof’s inflated edge creates a weather-protective seal at the inner edge of the permanent roof.
“SEFAR Architecture’s TENARA Fabric’s composition makes it inert – delivering environmental resilience and a long-lasting, high-quality architectural finish,” says David Campbell, President of Geiger Engineers, the engineer of record on the project.
Revealing over 89,729 square feet of clear blue sky, the new retractable roof allows BC Place to tailor the atmosphere for any event. In the past, the facility had to turn away events due to the sealed air configuration that prevented natural light transmission and caused heat and humidity issues during the summer. Now, BC Place is equipped to handle summer festivals and concerts under the sun, football games under the stars, indoor exhibits protected from rain and much more.
“The new retractable roof is an incredible feature of the newly revitalized BC Place,” says Howard Crosley, General Manager of BC Place. “Not only does it make a one-of-a-kind architectural statement, but the unique TENARA Fabric also allows more light into the stadium than ever before. Ultimately, the roof gives us the ability to control the atmosphere at BC Place for any event – day or night, rain or shine – providing the best possible experience for our guests.”
The facade is made from 144 transparent ETFE panels that protect the facility’s 55,000 spectators from inclement weather. The outer fixed roof is made out of 36 glass/PTFE panels. The new roof system is more energy efficient than the previous air-supported roof, saving the facility 25 percent on energy costs.
The retractable BC Place roof features TENARA Fabric’s 4T40HF, which offers 40% light transmission. TENARA Fabric is woven from high-strength expanded ePTFE fluoropolymers, and is also fluoropolymer-coated, making PTFE inherent in the material. This provides the fabric with the ability to flex and fold without wear or losing strength. The material will also not crack, crease or develop mold or mildew while stored.
“TENARA Fabric provided the durability, strength and foldability that we needed for this ambitious pneumatic retractable membrane roof,” says Campbell. “In addition, TENARA has the high light transmission we desired for the retractable roof at BC Place. It greatly enhances the roof closed daylighting of the system.”
“We chose to design with TENARA because of its folding capabilities and translucency,” says Christoph Paech, Project Manager for Schlaich Bergermann & Partners, roof design engineer on the project. “We performed several tests during the design phase, including a folding mock-up, and as a result the engineering of the roof was straightforward and successful.”
BC Place originally opened in 1983 and was the world’s largest air supported dome stadium until it closed in April 2010 for renovation after serving as a venue during the 2010 Olympic Games. The $563 million revitalization project also included a new all-weather turf playing surface, upgrades to the mechanical, electrical, lighting and sound systems, enhanced entrances and concourses, outdoor landscaping and replacement of 50,000 seats.
The facility is the largest sports, exhibition and entertainment venue of its kind in British Columbia and home to the BC Lions Football club and the Vancouver Whitecaps Major League Soccer franchise.
To view a video of BC Place’s retractable roof, visit: http://www.sefarag.com/bc-place-retractable-roof.
To learn more about SEFAR Architecture’s TENARA Architectural Fabric, visit http://www.tenarafabric.com.
The BC Place project was completed in September 2011. Members of the project team include architect Stantec, Edmonton, Alberta, Canada, engineer of record Geiger Engineers, New York, New York, engineer Schlaich Bergermann and Partner LP, New York, New York and engineer Tensys, Bath, UK. Hightex GmbH, Rimsting, Germany, was the fabricator and installer for the retractable roof and the outer roof.
About SEFAR Architecture: SEFAR Architecture is a leading manufacturer of monofilament precision and ePTFE yarn fabrics and fabric systems for interior and exterior architectural applications. With comprehensive knowledge in textile architecture, Sefar has cooperated with experienced lighting technicians and polymer experts to develop a new generation of fabrics for the architectural and design community. For more information on SEFAR Architecture’s products and services, call Peter Katcha at 727-388-4919 or visit www.sefar.us.