Glass Curtain Wall and Window Wall systems: What’s the difference?

January 13, 2023
Posted in Curtain Wall
January 13, 2023 admin

During our design meetings and scope reviews, a brave soul will often ask, sheepishly but courageously, “So, what exactly is the difference between the glass curtain wall and window wall?”

While most of the room gives them the “that’s a dumb question,” everyone thinks the same thing. After all, a curtain system is defined as “an outer covering of a building with non-structural outer walls.”.” The wall can be made of bricks, glass, or other materials. We shall focus on the curtain wall as it relates. We try to provide a broad overview of curtain wall and window wall systems in this post.

Even the glass and glazing industries sometimes have differing views on defining the two systems. There are projects and applications where one method is preferred over the other, but they are sometimes interchangeable. Many factors must be considered, and only after thoroughly understanding a project’s goals and design intent can one determine which system best suits a specific task. Because this subject comes up regularly, we would like advice on how to view the two solutions.

This article’s objective is not to provide a thorough analysis of fenestration systems but to give you some high-level understanding regarding window and curtain walls so that you can make better decisions for your upcoming projects.

 Glass Curtain Wall Systems

In general, curtain wall systems are non-load bearing since they are attached to the exterior of the floor slabs and function as a “curtain” that is physically hanging on the building. It spans from slab to slab, and systems are typically built in one of two ways: stick-built or panelized. Stick-built curtain components are delivered directly to the job site and assembled before installation. Panelized curtain walls are prefabricated units built in a controlled shop environment. The units are delivered to the job site, ready to be anchored to the floor slabs.

Curtain wall systems are available in standard depths ranging from 6 to 10 inches, with the ability to go deeper depending on the manufacturer. Deeper systems offer more support without requiring steel reinforcement. When there are more than 15 feet between slabs, glass curtain systems are the best option.

Curtain wall provides superior structural strength in both stick-built and unitized systems. The fenestration system “locks” together, providing excellent resistance to high wind loads and earthquakes. Curtain walls can accommodate larger glass sizes than window walls due to their high structural strength. Small cranes and boom lifts are frequently needed to install curtain walls because they are attached to the exterior of a structure, and the installer typically supplies them. Panels can be lifted from the floor where they will be installed or from the ground.

Glass curtain wall advantages

There are numerous reasons to choose a curtain wall system, the most obvious of which is the ability to produce specific aesthetics. It is possible to create a continuous “curtain” of glass on the outer façade because the curtain cladding is attached to a building’s exterior slab.

Another reason for choosing a unitized curtain wall is that quality can be controlled at a high success rate because the panels are built in a controlled shop environment.

advantages of curtain wall systemsCurtain wall disadvantages

Curtain wall systems present several common challenges. The curtain system leaves a void from floor to floor since it extends past the slab border. This void necessitates the inclusion of fire-stopping materials. Furthermore, noise transmittance can be an issue. There are, however, high-quality options for significantly lowering noise transmittance levels in curtain wall systems.

While window walls can be less expensive, glass curtain cladding can be more expensive depending on other circumstances. Curtain walls are long-lasting and only need a little upkeep over time. Additionally, fewer person-hours are required in the field because unitized curtain cladding systems are constructed in a controlled shop environment, allowing for the achievement of more rigid timelines. When comparing the cost of unitized curtain walls to alternative methods, the savings brought on by labor efficiencies in the factory and the field frequently ease financial worries.

disadvantages of curtain wall systemsWindow Wall

Window walls sit between the floor slabs, as opposed to curtain walls. The window wall is similarly constructed in a shop and delivered pre-assembled to the site like a unitized curtain wall is. Caulking seals the units once they have been fastened at the head and sill. Additionally, the non-load bearing is the window wall. Fire-stopping is not required because the window wall is positioned between floor slabs. Additionally, in some situations, noise transmission may not be as much of an issue as with curtain claddings.

Window walls typically reach up to 12 feet from floor to floor. Beyond that, it will be necessary to add steel to the vertical mullions to strengthen the structure. Window wall installation can be done from the inside or the outside, depending on the project’s requirements.

Window walls’ aesthetics are very different from curtain walls’. During the project’s design phase, architects must consider the exposed slab edge. Metal panels can be used in the facade in various inventive ways that cover the slab edge and interact with the window wall system. On more minor scales, some window wall systems can mimic curtain claddings, but nothing comes close to replicating the seamless appearance of a curtain wall system on large-scale facades.

window walls for commercial buildingDepending on the architectural objective, there might be other options than the window wall. For instance, window walls are not the most excellent option if your project involves a 40+ story building and you want a continuous outside glass facade. Because it lacks the structural integrity and strength of the curtain wall, the height of each project is a crucial factor when comparing the two systems.

Window walls are typically less expensive per square foot than curtain walls, though management costs for the exposed slab edge must be considered. Additionally, there are many caulk joints on window walls, which might increase long-term maintenance costs.

Another popular option for glass buildings is spider glazing or spider point glass which we recommend you check out.

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