The Nancy and Rich Kinder Building at the Museum of Fine Arts, Houston Takes Shape with New Glass Technologies

By Ellen Rogers

Light dominates much of the work from Steven Holl Architects (SHA); Holl himself has even referred to light as his favorite material. So it’s not surprising that the façade of the Nancy and Rich Kinder Building Museum (the Kinder Building), a part of the Museum of Fine Arts, Houston (MFAH), continues the firm’s 40-plus years of research into translucent materials. Completed in November 2020, the Kinder Building features a
complex façade of thick translucent glass tubes, used for both aesthetics and energy performance. As the firm describes it, “… we experimented in our shop with semi-opaque shapes and textures in light. Using acrylic rods, which we cut in half and laminated to acrylic sheets, we discovered the internal glow and arcing variation of light and reflection across the curved surfaces that is now visible in the building.”

Creating this reality wasn’t easy. It required careful and consistent communication and coordination with all parties involved, and meant designing, developing and testing new ways to use glass.

The Curves

At first glance, the milky half-tubes that comprise the Kinder Building’s façade might not look like glass. But they are. The curved glass, measuring between 4.5 meters and 6 meters long, was constructed of 8-mm low iron laminated glass, fabricated by Shennanyi in China and installed by Josef Gartner GmbH. Knippers Helbig, with offices in New York and Germany, was the façade consultant.

Having worked on two other SHA projects, Gartner was familiar with the firm’s work with light. The first project was the Lewis Center for the Arts at Princeton University. Felix Schmitt, Gartner’s head of design and engineering in Würzburg, Germany, says this was an intensive collaboration where they learned SHA’s philosophy [around the] interaction between light and shadow through different glass build-ups to reach transparent and translucent. “We were also able to implement this philosophy in the second project, The REACH at the Kennedy Center in Washington, D.C. The MFAH then presented us with a new challenge in the design of the exterior façade of the building.”

Roman Schieber, associate director with façade consultant Knippers Helbig, says his firm worked closely with Gartner on this design-assist project.

“We started talking to suppliers and contractors after schematic design of the curved glass. This started very early and we were involved all through the mock-up process. Basically, the entire building envelope is wrapped in translucent glass tubes and behind the tubes there’s an open catwalk area in between the glass tubes and the actual weather wall,
which is concrete with punched windows. The courtyards are cut out of this volume and not covered with the tubes.”

Schieber says the majority of their time was spent on the glass façade, which was a very complex geometry consisting of the translucent glass that brings daylight in the gallery. According to SHA, the bent glass rain screen is a new cladding concept that required starting from scratch in terms of engineering and detailing. The firm developed this geometry in full scale into a series of bent, laminated glass tubes with semicircular sections. The section shape provides structural properties that allow the glass tubes to span up to 19.5 feet with a bending radius of 1’-2-5/8. The façade features 1,103 pieces of glass with 459 different sizes. The bent glass pieces are suspended from the exterior concrete walls of the building with a steel support structure, which consists of steel tube outriggers cantilevering off the concrete, spaced 7 feet, 6 inches apart. This creates a cavity between the concrete wall and the back of the glass tubes. The glass tubes rest on small stainless-steel shelves for deadload support while the lateral support consists of four aluminum clips (one in each corner), siliconed to the back of the glass. The semi-circular geometry, which provides structural strength, was analyzed in depth by both Knippers and Gartner. Likewise, SHA worked with climate engineer Transsolar to learn about the ecological potential of this system, setting the tubes off the exterior wall to create a 3-foot-wide cavity open at the top and bottom. They found that the low transmission of the translucent glass bounces much of the solar gain off the façade. The 30-inch tubes of glass, which are open at the top and bottom, provide what the design team calls a “cold jacket.” This reduces solar gain by 70% on the façades via the chimney effect of air circulation.

A full-size mock-up of the cold jacket was built at the Gartner plant in Germany, which Schmitt says helped them verify the progress of installation on site.

“What’s important is that the glass is not just an architectural feature, but is part of a sustainable concept. Most of the year it is hot in Houston, so it’s important to reduce heat gain. It’s easier to work with artificial light because the daylight changes color throughout the day, time of year, etc., so we did daylight simulations,” says Schieber. No software can precisely predict daylight through such a complex glass make-up, and it can be difficult to analyze. So we built a half-scale mock-up of the full gallery and calibrated the glass make-ups. There was more light in the mock-up than expected so we made several minor modifications, with the coating, interlayers and added  a fritting on some of the clerestory glass. Making it even more complicated was the UV radiation, so we had to be sure the daylight coming through the glass would be the non-critical part of the UV spectrum.”

In addition to the translucent façade, the project also includes spans of clear glass curtainwall. These portions include 8,200 square feet of SunGuard SuperNeutral 62/34 HT coating on UltraClear glass from Guardian Glass that was fabricated by Eckelt in Austria.

In the Details

The glass tubes were fabricated in China by Shennanyi, and each took about eight hours to produce, according to Schieber, who says there was a lot of discussion early on about how to bend the glass.

“We started doing the testing early because tubes of that size and radius hadn’t been done before. It was a trial and error to find what exactly is feasible in terms of radius, tolerances, etc. No one could really say what the remaining stress in the glass would be after [curving] and that is what we had to fi nd out,” he says. “We built fullscale tube samples. [During the tests] we increased glass thickness and the diameter slightly; we did more tests … so it was a long process. But during the entire fabrication process we all agreed on quality control tests on the tubes to avoid surprises later.”

For the uniform surface, the outside of the glass structure has an acid-etched surface. The glass is also laminated with the Vanceva Artic Snow interlayer. Schmitt explains that since there could be no visible fixings of the semicircular glass tubes, they had to use a fixing system of metal elements with structural silicone on the inner side at the four corners.

“This task resulted in an intense investigation with finite element calculations and testing, as well as full-sized samples of different glass built-ups to achieve best visual appearance,” says Schmitt.

In addition to working closely with the glass fabricator and façade consultant, Schmitt says a direct coordination with Dow, the structural silicone supplier, was also necessary.

“The client did provide the windload assumptions for the building and a record of temperature recordings at different positions on the glass surface. They were recorded over a period of several months [from] original glass samples hanging on a performance wall in Houston. A classification of the glass joints was developed together with the architects. Similar tests were performed on original sizes. All this data were then imported into a structural model for Finite Element Analysis and led to different solutions at different areas of the building. Additionally, a special quality control system was developed and specified for this building, to allow a safe glass product for all processes from glass production, transportation to final installation.”

Schieber adds that there were still some challenges, particularly given that the highly complex glass was being produced so far from the jobsite.

“They (Shennanyi) only had one person who could speak English, so communications sometimes wasn’t easy. We flew to China to meet them and to build a personal relationship and to see how they fabricate and their efforts to make this happen, and they also came to our offices in Germany,” he says.

As far as shipments or delays, Schieber says there weren’t any real issues. “A few tubes broke during installation, which had to be re-ordered, but the glass tubes aren’t necessary to make the building water tight. The last tube, per the schedule, was installed five or six months before the opening. On other projects you’re working until the last day; but on this one the façade was done early.”

Façades continue to become increasingly complex; the Kinder Building is proof of that. That complexity comes not only in the design and aesthetics, but the strides projects are taking toward performance and sustainability.

“We really made a big step in terms of working with daylight and glass. Climate change is happening and whatever we can do to make buildings more sustainable will keep us busy,” says Schieber. “Yes, the glass tubes are an architectural feature, but at the same time it’s very sustainable.”

Ellen Rogers is the editor of USGlass magazine. Follow her on Twitter @USGlass and like USGlass on Facebook to receive updates.

To view the laid-in version of this article in our digital edition, CLICK HERE.