Most Innovative Curtain Wall Project
Bellwether Design Technologies, www.bellwetherdesigntech.com
The “Crinkle Wall” curtain wall is the signature design element of the Hyatt Place in Portland, Maine. “The expression we were aiming for was that of pleats, or folds, like you’d see in fabric or clothing,” says Tim Hart one of the founding members of Canal 5 Studio, www.canal5studio.com, the project architect. “This, of course, introduces great complexity into the geometries, and ultimately the design, fabrication and installation.”
Canal 5 Studio looked to Bellwether Design Technologies to develop the curtain wall, and the project-specific system was custom designed starting with the dies to meet four strict criteria: unique aesthetics, performance, ease-of-installation and budget. Bellwether’s “adventurous spirit in combination with their technical competence enabled us to realize that which we literally could only imagine,” Hart says.
The system had to manage extreme and varying angles in both vertical and horizontal mullions, while blending visually with an adjacent off-the-shelf curtain-wall system used at street level. Maintaining clean lines of the structurally glazed system was a key consideration, as the aesthetics needed to be more about the glass than the metal.
Bellwether minimized complexity by introducing split horizontal mullions at each slab level. “To use typical curtainwall construction at vertical joints would introduce compound, bent splice plates and exposed fasteners, adding cost and bulk to the system,” says Mike Maguire, Bellwether’s director of design and engineering. Bellwether’s horizontal split mullion allows for clean transitions between adjacent planes, without visible fasteners, he reports.
“The obvious challenge is making linear materials flow like fabric. The innovation comes with the non-conformity of the system, i.e. the offset lites and every joint being a compound mitre,” says Tobias Parkhurst, president of glazing subcontractor O&P Glass, www.augustamaineglass.com.
Each mullion was fabricated on CNC equipment to achieve accuracy to within a few thousandths of an inch. When the starter sill was initially installed, it was used as a precise template to verify the curb layout.
System performance is achieved through structurally glazed design. Consistent joint widths of the silicone weather seal were maintained by designing insulating glass units with cantilevered inboard and outboard lites on any of the four edges based on whether it was an inside or outside corner.
Ease-of-assembly was achieved by designing the system to be factory-assembled as horizontal ladder sections that could be installed one floor at a time. The system anchors to steel tabs at the edge of the slab, with nesting channels at the split mullion.
The glass is 1-inch insulating, with one lite of ¼-inch clear tempered glass with Cardinal 272 low-emissivity coating on the No. 2 surface, a ½-inch airspace, and a ¼-inch clear tempered lite. Each glass unit is a unique trapezoidal shape, with offset inboard or outboard edges on two or three sides. Prelco, www.prelco.ca, was the glass fabricator.