House of Air Trampoline Facility Wins National Architecture and Engineering Award
August 1, 2011 from American Institute of Steel Construction
(Chicago, IL) – The House of Air trampoline facility at Presidio Building 926 in San Francisco has earned national recognition in the 2011 Innovative Design in Engineering and Architecture with Structural Steel awards program (IDEAS2). In honor of this achievement, members of the project team will be presented with awards from the American Institute of Steel Construction (AISC) during a ceremony at the House of Air location at the Presidio in San Francisco on Monday, August 1, at 2 p.m. Conducted annually by AISC, the IDEAS2 awards recognize outstanding achievement in engineering and architecture on structural steel projects around the country. The IDEAS2 award is the highest, most prestigious honor bestowed on building projects by the structural steel industry in the U.S.
Project team members include owner House of Air, San Francisco; architect Mark Horton Architecture, San Francisco; structural engineer Holmes Culley, San Francisco (AISC Member); general contractor Hathaway Dinwiddie Construction Co., San Francisco.
The House of Air trampoline facility is a Merit Winner in the category of projects Less than $15 Million, making it one of only six projects around the country to receive the Merit honor. Each year, the IDEAS2 awards honor National and Merit award winners in three categories, based on constructed value: projects less than $15 million; projects $15 million to $75 million; and projects greater than $75 million. Each project is judged on its use of structural steel, with an emphasis on creative solutions to project requirements; design innovation; aesthetic and visual impact of the project; innovative use of architecturally exposed structural steel; technical or architectural advances in the use of steel; the use of innovative design and construction methods; and sustainable design.
In 2010 two young entrepreneurs with an interest in action sports opened House of Air, a trampoline facility that caters to the young, energetic population of active San Francisco. The single-story, steel-framed building is a historic aircraft hangar located at the western end of Crissy Field and the foot of the Golden Gate Bridge within The Presidio of San Francisco, a national park.
The facility includes more than 6,500 sq. ft of conjoined trampolines. A large field trampoline for bouncing sits alongside a trampoline dodge ball court and three performance trampolines used fro competitive jumping and ski, snowboard, and wakeboard training. Flanking the trampoline area is 10,000 sq. ft of amenity space including two pavilions housing a café, meeting facilities, lockers, and a lounge. Translucent blue walls lit from within are graphic interpretations of the vertical motion which takes place throughout the facility.
The client’s objectives were purely to construct and operate a facility that could accommodate their business plan. The architect’s objective was to create a space that would act as a branding device in a visual manner, thus elevating what could otherwise have been a base commercial experience to a level matching the sophisticated site and clientele.
The seismic strengthening of the structure included new ductile steel special moment resisting frames, which are integrated into the existing building with a tension rod roof diaphragm. The strengthening scheme was carefully detailed to minimize the impact on the existing building fabric and allowed many of the building’s character-defining features to remain.
“The more this is studied, the more impressive are its attributes,” commented Wesley Walls, AIA, Polk Stanley Wilcox Architects, Little Rock, Ark., a judge in the competition.
The Presidio has stringent requirements for maintaining the history behind its existing buildings. As with most historically significant buildings, the way in which they were built tells a story about both construction practices and social and economic circumstances at the time. Maintaining the story associated with this historic biplane hangar was an important driver for the approach of the project. Very little of the original building fabric was removed and the inherent strength of the existing structure was used to the greatest extent possible. Additionally, the House of Air project is LEED certified with many of the credits coming from the reuse of existing materials.
The renovation and remodeling of the existing historic hangar was no small task. The existing building consists of a steel trussed roof spanning 110 ft. Steel columns support the roof at the perimeter creating a 17,000-sq.ft column-free floor plate. The existing structure is built on artificial fill prone to liquifaction in a high seismic zone. Additionally, the 3-in.-thick concrete roof structure – bomb-proof by 1920s standards – which had to remain intact, made it clear that the building was in need of strengthening.
Providing a cost-effective and efficient method to strengthen the building and develop details for the new trampolines to accommodate the uneven slab were the two most difficult tasks the design and construction team had to address.
The final solution provides isolated strengthening to the existing gravity truss top chords which could then be used as compression members in a new roof diagram. New diagonal rod bracing, 2 in. in diameter, was installed to complete the diaphragm “truss” while the out-of-plane reactions resulting from the change in roof pitch are resisted by the strengthened gravity trusses. By addressing these two issues in unison, the design team was able to limit the addition of new material to an existing historic building and deliver a diaphragm stiff enough to project both the existing gravity frames and the brittle concrete roof.
Investigating materials at the outset of the project showed that the original steel was suitable for welding, which facilitated the integration of the new lateral bracing and gravity strengthening, one of the many advantages of using structural steel.
In addition to the base building seismic retrofit and core and shell work, the structural engineer designed a vast network of conjoined trampolines, providing detail as well as structural calculations and drawings to meet the requirements of the California Building Code.
The design required complex analysis of the individual trampoline framing members. The trampoline framing uses more than 6,500 ft of HSS and were modeled in Revit to simplify the fabrication and installation process. A system of adjustable legs detailed to accommodate more than 5 in. of undulation in the existing hangar slab. That permitted fabricating all trampoline legs the same length while at the same time allowing the trampoline beds to be perfectly level. By using a section of threaded rod and locking nuts for each leg, its overall length could be shortened or extended to suit its location by simply spinning the base plate, saving a significant amount of time during the 350-leg installation.
The 14 IDEAS2 winners for 2011 were chosen from nearly 100 submissions received by architectural and engineering firms throughout the U.S. Each submission is reviewed and award winners are selected by a nationally recognized panel of design and construction industry professionals.
The IDEAS2 award dates back over 70 years to the earliest years of AISC’s existence. Roger E. Ferch, P.E. president of AISC, said, “The entire House of Air project team has shown how structural steel can be used to create structures that combine beauty and practicality. The result is a recreational facility that serves its patrons extremely well, while providing an example of what can be achieved when designing and constructing projects with steel.”
View and download high resolution images of the House of Air trampoline facility in a slideshow gallery of photos available here.
Photo by Kaplna Photography
For more information contact:
American Institute of Steel Construction
The American Institute of Steel Construction, headquartered in Chicago, is a not-for-profit technical institute and trade association established in 1921 to serve the structural steel design community and construction industry. AISC’s mission is to make structural steel the material of choice by being the leader in structural steel-related technical and market-building activities, including: specification and code development, research, education, technical assistance, quality certification, standardization, and market development. AISC has a long tradition of service to the steel construction industry of providing timely and reliable information.
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