Making the Case for Window Walls

by Marcy Marro | December 1, 2021 12:00 am

Many factors go into creating the right daylighting—the type of window, window placement and interior design help to control how sunlight comes into a building. However, one of the most important decisions hinges on the right facade solution.

While curtainwall is typically first thought of for high-rise applications, window wall offers significant advantages in today’s market in which clean design, quick installation and cost advantage are critical.

At-a-Glance: Window Wall versus Curtainwall

Commercial buildings have traditionally been built with curtainwall. In recent years we’ve seen a desire for architects to design more creatively, with less. As a result, window wall has emerged as the preferred system for mixed-use buildings.

While curtainwall systems are designed to sit in front of the building and anchor to each floor line, window wall systems rest inside the building and span floor-to-floor. This creates an inherent cost advantage over curtainwall systems, as structural requirements can be met with less material and reinforcing.

A key attribute of window wall systems is the ability to install and glaze from inside the building. This attribute is enhanced by the recent trend of pre-glazing, which further shortens installation time and requires less labor.

Paired with innovative slab edge covers, which add architectural detail to a building, window wall provides architects with a modern, clean look and maximum design versatility. It mirrors the look of curtainwall from a building’s exterior, while providing high thermal and acoustical performance.

Window wall also lends itself well to being a flexible option amongst various projects. For example, window wall systems are specifically designed with anchoring flexibility so they can react to challenging wall conditions. Curtainwall isn’t as adaptable.

As design trends veer more modern, architects are also calling for more operable windows and zero sightline vents. Window walls are great for punched openings and ideal for inserting operable products to simulate historic looks, like steel windows, or to add natural ventilation.

Consider This: Acoustics

As prime downtown locations become scarcer, developers look to build on less desirable sites near freeways and airports. This fuels the need for better acoustical performance.

While there are many aspects of interior spaces that can make an environment comfortable, like sound-absorbing surfaces and interior partitions, exterior facades are key. Unlike curtain wall, window wall is a slab-to-slab application. This means that the window wall stops at each floor. As a result, it does not transmit sound waves from floor-to-floor, creating better sound attenuation. This provides specifiers with more control over acoustical performance, particularly in mid- to high-rise residential and multifamily applications where acoustics are highly valued.

Case in Point

In the heart of Music City, U.S.A., sits the 33-story glass tower that is the JW Marriott Nashville. Its curvilinear shape has become an iconic addition to the city’s skyline. The systems were designed with innovation, performance and economics in mind. But what looks like a simple, straightforward design was actually quite complex.

John McGill, manager of the project center at YKK AP America, recalls the initial stages of the project. “The overall shape and configuration of the building, and the sheer size and scope of it were some of the things that truly set it apart. How to be able to design a system that would accommodate the large scope and still be done in an economical manner, while providing for easy installation from the inside of the building … these were all very challenging aspects to the project.”

While examining the design, engineers identified a total of 25 different angles to create the desired elliptical shape with a continuously changing radius. Rather than using a curtainwall, which was originally specified in the design, the team turned to a window wall system. Because the window wall system was designed with anchoring flexibility, it was able to react to challenging wall conditions.

The end result achieved the same look and feel as curtainwall, at a more reasonable price point.

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Steve Schohan is marketing and communications manager at YKK AP America Inc., Austell, Ga., where he develops marketing strategies and leads research efforts on emerging markets and trends, with an emphasis on driving industry product evolution and innovation. Schohan has more than 25 years of experience in the construction, home improvement, retail, and consumer products industries. For more information, visit www.ykkap.com[1].

Source URL: https://www.metalarchitecture.com/articles/making-the-case-for-window-walls/

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