Architectural Choices
Fortunately for architects, the advancing of design support technology has led to a wide range of products that help designers to understand materials and items that control the amount of daylight that streams into buildings. Glass is one of the main engineered solutions.
“There is a tremendous amount of technology and an unbelievable amount of glass types,” says Lewis. “They all do different things. They let in a certain amount, or block out light, some look different, and some perform better from a thermal standpoint. There is a lot of science behind the glass these days, and that’s the first line of defense in planning decisions.”
Johnson County Community College offers an example of a project that meets multiple objectives. The college’s Fine Arts and Design Studio is enveloped in a customized ventilated glass façade that filters soft, glare-free daylight into the studios.
The 52-m (170-ft) wide façade includes fritted glass laminated to etched glass on surface #4 to create a strong, light-diffusing effect. Behind the translucent glass façade, traditional windows fill the studios with soft, glare-free, filtered daylight. The secondary glass façade is also designed so it can double as a projection screen for student art, eventually transforming into a lit canvas.
It also prevents moisture damage and shields the structure from rain and wind. On the interior, hallways are clad in magnetic glass marker boards with a special matte finish, specified to eliminate harsh reflections and glare.
The Kean University project took a different path. In this case, architects specified 162.5 m2 (1750 sf) of channel glass with 25 to 40 percent post-consumer recycled content in two different textures. The double-glazed channel glass walls effectively manage daylight, while also controlling water drainage and thermal transfer. The project won an award from the American School & University, which praised Liberty Hall’s “good use of texture and light to provide vitality” and its dynamic spaces and detailing.
Channel glass is a versatile specialty product for exterior and interior wall applications, which can be used in everything from façades to interior partitions. It provides soft, even light distribution. Channel glass can be specified in a range of bird-friendly textures, performance coatings and insulation options, delivering U-value ranges from 0.49 to 0.19, and VLT ranges from 72 to 37 percent.
Bird-safe glass is guided by a “2×4” rule, which presents an easy formula for an effective glass solution. Essentially, it stipulates horizontal design elements should be placed no more than 51 mm (2 in.) from each other, and vertical design elements should be spaced no more than 102 mm (4 in.) apart.
More and more communities are requiring bird friendly glass on new construction and major renovations. For instance, New York City adopted legislation requiring bird friendly glass on new construction in 2020. Further, the American Bird Conservancy is advocating a bill to enact nationwide bird friendly guidelines for federal buildings.
“There are some interesting textural opportunities with channel glass you don’t see as much in contemporary glazing systems,” says Lewis. “You can also get much larger expanses of glass. With a single sheet of channel glass, you can also get 23 ft (7 m) vertical coverage. This expanse of conventional glazing would be quite expensive, and it would need structural support. Channel glass can be clipped in, so it’s easier and faster to install.”
Wernick says windows are also an important architectural tool and can be used in a variety of ways.
“In an entryway, we might use a lot of windows to welcome people and to designate an important piece of the building,” she says. “Windows are a great tool for providing variety and differentiation across the building and are used to define the exterior form through solid-void relationships, as much as they are used to allow daylight to define interior forms.”
Wernick, who has been designing schools for almost 40 years, says she also incorporates light shelves into her projects that reflect light deeper into spaces and help reduce glare near the exterior wall.
“A light shelf can be a solid or translucent surface inside or outside the window located above the viewing portion of the opening,” says Wernick. “It is intended to simultaneously bounce daylight deeper into the space in conjunction with a high and reflective ceiling and reduce glare at the viewing portion of the window by shading it.”
The use of glass façades, scrims, windows, skylights, and other solutions that allow natural light must be balanced with thermal performance. Student performance, heat gain, and cooling loads, as well as community budgets are all important factors to consider.
