What do skyscrapers with towering walls of glass windows glinting in the sunlight and luxurious floor-to-ceiling windows overlooking snowy mountains have in common? Those glass elements are likely curtain walls!
Curtain walls create beautiful facades, unforgettable views, and unique personalities in buildings and homes. When done with an expert eye for design and use of certain materials, they can also be a part of a passive building or other green building certification strategy. If you’re interested in centerpiece design elements or reducing energy usage (or both!) in your construction project, here’s what you need to know about curtain walls:
What is a Curtain Wall, exactly?
Curtain walls are non-loadbearing walls that use aluminum frames around large glass panes and are used in both residential and commercial buildings. The frames are anchored to the floor slabs of a building, meaning they “hang” like curtains off of the structure. Additional engineering and structural elements are needed to offset weight across other areas of the building.
From the interior of the building, curtain walls offer uninterrupted panoramic views of the surrounding area. Depending on their cardinal positioning, they can flood a space with natural light, making curtain walls a popular choice for passive home building.
Curtain walls create a stunning facade of glass on the exterior of the building and can be customized to add utterly unique style elements to residential or commercial settings.
See how curtain walls play a role in the modern design of Martis Camp.
Considerations for Curtain Walls
If you’re thinking about curtain walls for your project, consider a few things before you jump in.
Curtain walls can be installed in a few different ways, and which method you use will depend on the style of the curtain wall, whether it's custom-developed for your project, and the fabricator developing the pieces. In general, curtain walls are delivered and installed in two ways:
- Stick System
- Units or Panels
In the stick system, the parts are delivered completely unassembled and all assembly, sometimes including appropriate glazing of glass panes, happens on-site during installation. While this process sounds more tedious for the construction crew, it may be required for complex, custom curtain wall facades.
Another installation option is using pre-built units or panels. In this method, curtain wall elements are delivered glazed and partially assembled in modules that fit together on the building like a puzzle. Using prefabricated panels is beneficial for large projects, like multi-story commercial buildings or projects that don’t require custom design and use standard parts.
Additional Safety Considerations
Because curtain walls are anchored at the floor slabs instead of between them, like window walls, there are some additional code considerations for safety. One consideration is the gap between the floor slab and the back of the curtain wall, which needs to be adequately sealed for fire safety. In this case, smoke seals must be added to these gaps to contain smoke and fire between floors properly should an emergency occur.
The specific requirements for your building will vary based on its location, purpose, and local and state laws, but it’s important to know that additional steps will need to be taken for fire safety when using curtain walls.
Green Building Requirements
As we mentioned previously, curtain walls create a huge opportunity to leverage natural light, a component of many green building certifications. If this is your goal, you’ll want to have your architect orient the windows to maximize natural light, depending on the geographical location of the building.
You might be concerned about how a wall of windows affects the heat retention of your building, which also impacts energy usage. But the right curtain wall system will feature construction and glazing that allow the glass to insulate the building and prevent unwanted heat exchange. Some curtain walls can also include opening elements to allow for controlled ventilation.
See Reynaers’ selection of super high insulating curtain walls.
Curtain walls offer unique design capabilities for your building. Since they’re anchored to the floor slabs of the building, they can create interesting shapes and designs on the exterior walls.
Curtain wall systems have been used for centuries, although they gained popularity after WWII, when aluminum became more widely available. Because of this history, curtain walls meld well with various styles across decades and into the future-focused, artistic eye. Whether you’re looking for something classically elegant or totally unlike anything else, curtain walls can help achieve your design vision.
See how curtain walls combined with exposed concrete create a unique facade to mimic large industrial windows on The Jackson building in Long Island, NY.
How Curtain Walls Differ from Window Walls
Curtain walls and window walls look similar; however, they’re not the same. While both curtain walls and window walls aren’t load-bearing wall features, the main difference is how they’re attached to the floor slabs. Window walls are attached between floor slabs while curtain walls are anchored off of them.
Where this attachment process matters is in additional considerations for the structure. Window walls don’t require the same fireproofing measures as curtain walls that we previously mentioned since there isn’t a gap between the slab and the wall elements.
Additionally, window walls are almost always delivered and installed in units, where curtain walls can be installed piece-by-piece. Curtain walls are also recommended for structures where the distance between floor slabs exceeds 15ft. This is due to how curtain walls connect together, which offers greater strength and more protection from “live” loads, like high winds or even earthquakes.
Consult with your architect or engineer about your building project's specific factors and dimensions to choose the right glass wall solution.
Curtain walls are a gorgeous addition to many building projects that add intrigue to the exterior design and provide masterpiece views from the interior. See how curtains walls are a part of residential and commercial buildings across the country in our inspiration gallery: