Curtain Wall or Window Wall: Depends on project goals and design aesthetics

What exactly is the difference between a curtain wall and a window wall?

We intend to offer a high-level awareness of window wall and curtain wall systems. There are very distinct projects and applications when one system is preferred over the other, yet sometimes they seem interchangeable. The system best suited for a particular project depends on the project’s goals and design intent.

A 2017 study by the University of Toronto’s Building Tall Research Center and the Residential Construction Council of Ontario (RESCON) weighed the advantages and uses of curtain wall and window wall systems. Here are some of the key findings:

Window Wall

Window wall systems are installed between the floor and ceiling concrete slabs of a building. Units are anchored at the head and sill and sealed in place using caulking. Window walls are non-load bearing.

Advantages

• Less expensive, although the cost of managing the exposed slab edge needs to be considered
• Accommodate features such as balconies, operable windows, and suite compartmentalization
• Multiple units mean, fire-stopping is not necessary, repairs can be carried out with minimal disturbance, and decrease sound transmission between floors
• Installs quickly and easily, and requires less engineering

Disadvantage

• Weaker structural integrity, the system is built with more pieces (mullions) and joints, as a result, the buildings can look less aesthetically pleasing
• Number of joints increases the risk of failure
• Seals can dry out and crack, causing water to leak into the building, resulting in expensive repairs
• Building design needs to address the exposed slab edges

Curtain Wall

Curtain wall systems are continuous uninterrupted window framing that attaches to the outside of the floor slabs, acting as a “curtain” that is literally hung on the building and therefore, is non-load bearing. Curtain walls span slab to slab and are anchored using metal plates.

Advantages

• Excellent structural integrity, meaning fewer mullions and joints; as a result, the buildings can look more aesthetically pleasing
• Handles larger glass sizes, due to the structural strength
• Acts as a single unit, thus highly resistant to moisture, wind, heat, and earthquakes
• Requires less maintenance

Disadvantages

• Noise transmittance, however, high-performance options are available to significantly reduce noise transmission
• Cost, yet high durability, low long-term maintenance, and fewer installation hours can provide cost savings

Deciding between a curtain wall and a window wall system can be complicated. One isn’t “better” than the other – instead, it’s all about the desired end result. Which approach to choose will depend on the specific project and its needs.

St. Cloud Window offers a variety of window and door solutions. To find which one is better for your needs, contact us for an estimate.