Krueck + Sexton
Atop a brand new 36-story SOM-designed residential tower in Milwaukee, this two-story penthouse apartment boasts sweeping views of Lake Michigan, the city’s downtown, and the art museum by Santiago Calatrava and Eero Saarinen, easily explaining its nickname, the Cloud Residence. The 4,500-square-foot apartment’s interior was designed by Chicago-based Krueck + Sexton. It is a study in maximizing light and views while maintaining distinctive spaces and acoustic and visual privacy.
Nowhere is this more in evidence than in the glass and stainless steel staircase linking the two floors. The stair is composed of laminated glass treads on two stainless steel stringers, edged with a half-inch thick tempered glass panel balustrade hung from a stainless steel railing. In order to meet code requirements—Milwaukee forbids open stairs—the steel stringers have thin horizontal plates under the treads that act as kickers for the step below. The entire glass-and-steel staircase, which allows views from the living room through to the kitchen, rises from an onyx platform with embedded fiber optics, illuminating it from below. “We wanted the stair to be a sculptural object that would be as light as possible, while working within the constraints of code,” principal Mark Sexton said.
Glass appears throughout the apartment’s interior to maximize views and transparency. The architects designed custom sandblasted glass panels, made by Chicago-based Skyline Design, that are used as room partitions on the lower floor when hung from the 101⁄2-foot ceiling. On the upper floor, they become walls and sliding doors. A dot pattern is denser at floor level and becomes looser at the top, allowing views out while providing privacy below. The half-inch tempered low-iron glass is patterned on both sides, giving it a subtle appearance of depth. The sliding doors have a slim track in the ceiling, and none on the floor. The doors are braced at the bottom with a tiny steel bushing with a rotating nylon band. “Our drawings are stamped with symbols for ‘no frames’ and ‘no caulk’,” Sexton said. “We want it to look effortless. That’s the challenge of good architecture.”
The library, on the upper level, overlooks the double-height living room, separated by a clear glass railing, with expansive views out to the lake and city. “The ability to have as much natural light as possible allows the greatest variety of experiences,” Sexton said. “The space transforms throughout the day and over the seasons.”
Alan G. Brake
When asked to design the new headquarters for Vakko, a Turkish fashion and media company, the architects at REX were presented with an old, partially constructed concrete shell and an aggressive timeline to redesign the project. Rather than concealing the building shell—derelict structures like this are common in Turkey, where concrete construction is fast and inexpensive—the architects grew interested in revealing it through the thinnest sheets of glass possible. “We didn’t want to hide the adaptive reuse,” said REX principal Joshua Prince-Ramus. “This kind of adaptive reuse, of an abandoned, incomplete structure, is really at the forefront of sustainability."
The architects turned to the technique known as slumped glass, by which glass is repeatedly heated and cooled until it falls into a mold and assumes the mold’s form. Slumping is typically used to create decorative effects, but REX decided to use it for structural purposes: The glass panels feature an X-shaped impression that gives them vertical and lateral stiffness and strength. At 5 by 10 feet, the 134 panels that wrap the building are a wafer-like 3/16 of an inch thick. They are held in place by four simple pins at the corners.
Before the glass could be heated, however, molds had to be made. Wood composite forms were cut from jigs, and then ceramic molds were made from the impression of the wooden forms. The glass was then heated and cooled over the ceramic molds, using the same techniques used to heat-strengthen glass. The process would have been prohibitively expensive in many other places. “Turkey is at that sweet spot in their development where they have all the technology, but labor costs are low and they retain a large and highly skilled class of craftsmen,” Prince-Ramus said.
The effect, according to the architects, is something akin to Saran Wrap, with the glass appearing to pucker as if pulled taut. Startlingly clear when viewed straight on, the panes catch light and reflections when viewed from an angle. The facade is distinctive without resorting to heavy-handed branding or the overt decoration common in many prominent buildings for fashion companies. “Our client didn’t want a logo on the building,” Prince-Ramus said. “But they wanted something memorable.”
sarah blee/courtesy neutelings riedijk
Museum aan de Stroom
Ascending the escalators that spiral up Antwerp’s newly-completed Museum aan de Stroom, galleries displaying artifacts of the city’s past alternate with 18-foot-high views onto the city and waterfront. A competition-winning design by Dutch architecture firm Neutelings Riedijk, it comprises ten floors cantilevered out from a central core, each one rotated 90 degrees from the one below. Because many of the exhibitions’ contents will be sensitive to the sun, the galleries themselves have no windows, providing a stark contrast to the expansive panoramas on every other floor.
Those views are especially striking through the museum’s undulating glass enclosures. After winning the commission ten years ago, Neutelings Riedijk teamed up with glass engineer Rob Nijsse to devise a way of making their oversize panes thin enough to maintain clarity but stable enough to withstand wind, without resorting to metal supports. Their solution was to corrugate the panes, placing float glass in a wavy mold and baking it until it melted into shape.
Although the basic technique for curving glass dates to the 19th century, the unprecedented size of these panes raised a host of new problems. Only one other building had incorporated similar corrugated windows, to Neutelings’ knowledge: the 2005 Casa da Musica in Porto, by Rem Koolhaas, who worked with Nijsse as well. But the 18-foot panes in the Museum aan de Stroom were far larger, too large for most ovens to accommodate.
The team solved that problem by renting Europe’s largest oven, a 20-footer in Italy, but other difficulties remained. The hardest, according to principal partner Willem van Neutelings, was how to achieve enough precision in the dimensions of the panes to allow them to align perfectly and connect with silicone joints. “It took a lot of calculations and work with the glass industry to make it suitable,” Neutelings said.
The thin panes, unmarred by any metal reinforcement, seem to disappear when the museum is glimpsed from far away. When viewed from within the building, the corrugation is obvious. Standing inside the radius of one of the curves appears to create a private viewing chamber, with a much wider panorama than that of a flat window. Alternately, seen from a slant, the glass takes on a greenish tint, turning the window into more of a curtain and making the room feel enclosed. “What you see in the glass depends on your position,” Neutelings said.