Shedding Light on a Challenging Glass Curtain Wall System
KA’s Collaborative Design-Assist Process Overcomes Challenges of Budget, Schedule, Weather, Quality in Watford City, ND
Sunlight is probably not the first thing that comes to mind when you think of North Dakota. But if you ever visit the new Watford City High School and neighboring Watford City Event Center, you might change your view.
Currently under construction, the three-story, 160,000 s.f. high school and 269,000 s.f. event center feature glass curtain wall systems that maximize daylighting to each facility, promoting a strong learning environment.
That distinctive design element presents unusual challenges for delivery, particularly in the harsh extremes of the northern plains, where wind gusts of 50 mph, temperatures ranging from 30 below to more than 100 above, and driving rain and snow are not uncommon. Finding a solution that balanced design with quality, budget and schedule goals called for a multidisciplinary Design Assist (DA) approach. Below, members of the DA team recapped the successful effort.
Q: How did the Design Assist come about?
BRAD HARVEY, PROJECT MANAGER, KRAUS-ANDERSON: During the schematic design phase KA looked at several exterior options including storefront and curtain wall systems. When it was determined that a complete curtain wall system was the best design option, KA’s Mike Spence (VP of Quality) collaborated with JLG Architects to create a performance specification. Four curtain wall contractor proposals were reviewed and presented to the City and School boards for approval, and Ford Metro Glass (FMI) was selected. FMI in turn brought in Wheaton Sprague, a curtain wall design firm, as consultant.
Q: What were the specific challenges?
JOHN WHEATON, PRESIDENT, WHEATON SPRAGUE BUILDING ENVELOPES: The specifications asked for a Design Assist effort for structural work recognizing unique span heights, module widths, building structure conditions and integration required. It also needed an interactive thermal analysis for the Event Center, The High School and Pool area.
JERRY RICHARDSON, LEAD ARCHITECT, JLG ARCHITECTS: Of greatest concern for the high school project was the aggressive construction schedule required to deliver the building to the School District in January 2016. The timing of contract award, shop drawing review and coordination of curtain wall installation within the overall construction schedule were critical to meeting the completion and building turnover deadline.
Q: How did the process work?
HARVEY: KA coordinated a series of weekly online design meetings to review thermal imaging models, determine condensation points and to arrive at the mullion depths needed from a structural standpoint; and also to identify and address any other potential performance issues.
Q: How does the wall handle the intensities of wind and weather?
WHEATON: It handles the weather by having appropriate strength and/or reinforcing, and by being properly sealed within the context of the Wausau SuperWall system.
RICHARDSON: At the Northeast and west location the foundation wall and main frame structural steel had to be designed to account for higher load capacities than typical due to the cantilevered curtain wall condition. This required coordination among the architect, building structural engineer, curtain wall contractor, curtain wall structural engineer as well as KA’s team to be confident the extraneous loading and detailed connections were adequate for the conditions presented.
Q: How did the project team work together to come up with the design solution?
WHEATON: Through effective, planned, documented design assist meetings with all interested parties on board, with respectful dialogue, and with clear follow up activity and assigned tasks.
RICHARDSON: The KA construction team coordination and quality assurance process was critical in having all team players at the table to review and understand critical details of the curtain wall construction for the WCHS and WCEC projects. Every partner in the design process represented their experience and professional viewpoint at each meeting to maintain design intent while addressing performance and constructability issues.
Q: How did this solution expedite schedule and/or budget?
WHEATON: It allowed and facilitated real solutions in real time with all parties together and cut months out of the schedule (or kept a tight schedule on path). And it allowed budget decisions to be made on site in meetings.
HARVEY: By hiring FMI as early as we did they were able to complete their shop drawings and we shared structural and precast concrete wall panel shops to assist in this manner. As a result the curtain wall was fabricated from FMI’s shop drawings and arrived to the site as a preassembled unitized system with the glass already installed. The glass panels were hoisted into position section by section. This saved time in the field and expedited our finish schedule, a true win-win for the projects.
RICHARDSON: One aspect of curtain wall design and delivery process Kraus-Anderson addressed early on was the recognition of potential cost savings by bidding the curtain wall systems for both the high school and event center projects together. This presented substantial cost savings for both projects. Also, because both projects were bid together, the square footage of curtain wall to be installed met the area criteria requirement for a unitized curtain wall system assembly over a traditional on site stick built system. Thus advantages in schedule management, controlled environment factory assembly and quality assurance were achieved. Kraus-Anderson’s leadership, experience and knowledge enabled the installation of a high performance curtain wall system for both projects; providing years of service to the community.
Q: How does the curtain wall solution at the Watford City Event Center project differ from the high school’s system?
RICHARDSON: One key difference is the curtain wall system at the north and east walls of swimming pool at the event center. Pool environments present great challenges in curtain wall design, with summer like temperatures and high humidity inside while the outside winter temperatures may range well below zero. Wheaton Sprague was instrumental in providing design assistance in studying the overall thermal performance of the swimming pool curtain wall system. Early thermal performance studies showed that the typical curtain wall system would not perform as required. The final solution was to provide a triple pane insulated glass system and to eliminate the exterior pressure plate and cap instead specifying a structurally silicone glazed (SSG) system at vertical and horizontal frames.
The new Watford City High School will serve 800 students in grades 7-12 and is a joint venture with KA and Grand Forks-based Construction Engineers, Inc. Features include classrooms, cafeteria, commons, kitchen, multimedia center and learning resource center; gymnasium, cardio weight room, wrestling ring, theater, shop and band and choral rooms. Completion is scheduled for January 2016.
The event center will feature a swimming pool, field house with three basketball courts, two-sheet ice arena for hockey and skating, gymnastics facilities, football stadium with track, baseball and softball stadiums, convention space and a 3,000-seat venue for concerts and sporting events; plus parking lots, conference rooms and administrative offices. Completion of the event center is scheduled for September 2016.View Comments