More than Windows: Getting the Most from Architectural Glass

Devin Bowman, General Manager, Technical Glass Products

When people think of architectural glass, they may only imagine windows. While they are an important part of any building, windows are far from the only way glass can be incorporated into the built environment. There are several types of glass used in architecture—some of them are fire-rated, and some are not. Some are transparent, and others are translucent or completely opaque. In fact, some types of architectural glass do not look like glass at all.

Glass is truly a remarkable and versatile material. It can be used in door assemblies, curtain walls, load-bearing (and non-load-bearing) walls, floors, decorative features and much more. Glass meets a wide range of design aesthetics, and when responsibly manufactured, it can even contribute to green building initiatives like LEED and the Living Building Challenge (LBC).

The following will look at a few examples of what types of glass are used in architecture and reference case studies that show these materials in real life applications.

Transparent curtain walls

The benefits of daylight have been well documented for many different occupancy types. For example, access to natural light can have a significant impact on students, such as regulating circadian rhythms and potentially improving standardized test scores. While much of this research has focused on classroom design, it is also important to consider how spaces outside the classroom can contribute to daylighting goals, including main hallways, atriums and other common areas, that serve as meeting places and makeshift study areas.

Understanding the need for daylight in informal meeting areas, a combined middle and high school campus in Massachusetts renovated its existing facilities to include a light-filled common area. A floor-to-ceiling transparent curtain wall serves as a gateway between middle and high school classes. The architectural glass within the curtain wall also incorporates a transparent low-e film to improve thermal performance, helping the building operate more sustainably.

Door assemblies

Architectural glass can also be used in door assemblies, whether or not the doors require a fire rating. Glass doors allow visual connection between spaces to support an open design. For these assemblies, the framing systems are as important as the glass since they can be made to complement other material choices throughout a building.

For example, the La Crema estate at SaraLee’s Vineyard needed to create a barrier to heat, smoke and fire for its interior stairwell. The designers also wanted to maintain the rich allure of wood provided by the estate’s extensive framing and hardwood flooring. They turned to Fireframes TimberLine Series, which provides a narrow-profile steel sub-frame with a real-wood veneered metal cover cap. The system meets critical fire and life-safety code requirements while also creating a visual harmony between rated and non-rated features.

On the other hand, designers can opt for narrow-profile steel frames to create a door assembly that lets the glass take center stage.

Decorative channel glass interior and exterior walls

Channel glass is another type of glass used in architecture. Held within extruded metal perimeter frames, channel glass is self-supporting glass cast into U-shaped channels. Able to be specified in several levels of opacity from transparent to completely opaque, channel glass can meet a range of design considerations. And because this type of architectural glass can be single- or dual-glazed, it can be used in both interior and exterior applications.

The result of using channel glass can be quite stunning. It can follow curved exterior walls while diffusing light gently throughout a building’s interior. It can also be used within a building for an ultra-modern design aesthetic. With its ability to span lengths up to 23 feet, channel glass systems can meet the structural demands of a monolithic glass façade design.

Further, because it can be specified with transparent Lumira® aerogel insulation, it can contribute to energy efficiency with u-values as low as 0.19.

Which type of glass is used in architecture depends on building need

These are just a few common applications of architectural glass. Glazing can be an important part of meeting many different design criteria, including less common considerations like X-ray shielding, while also supporting visual connection between spaces.

With such varied uses and configurations, architectural glazing has the potential to realize designs that were not possible 20 or even 10 years ago. However, such versatility can make it difficult to know all the options available, so architects are encouraged to reach out to manufacturers and ask questions to ensure they are choosing the right systems for their projects.