How to Design a Curtain Wall

The term ‘curtain wall‘ is commonly used to describe the glass and metal elements of modern high rise buildings that separate the occupants and structure of the building from the exterior environment. While curtain walls have many benefits, they also create a number of design challenges.

The curtain wall is a significant part of the primary building structure and must transfer back to floor structure or intermediate framing both its own dead load and the live loads that are applied, which include wind induced loads, snow loading on large horizontal areas, seismic accelerations and maintenance loads. Additionally, they must be designed to allow differential movement due to thermal changes that are significantly different from the movements of the primary building structure.

Transparency and Strength: Exploring the Advantages of Curtain Walling Systems

Curtain walls can be constructed in two forms; “stick systems” and “unitized systems“. Stick system curtain wall construction consists of individual vertical and horizontal spanning members, known as mullions and transoms, that are installed separately from the main building frame and joined together on site. Unitized curtain wall construction is factory fabricated and assembled as complete units that are installed on the building structure to form the building enclosure.

Both types of curtain walls require careful planning for their installation. The selection of an installation contractor who is experienced with both stock and custom systems will help to avoid costly errors. In addition, a field mock-up should be constructed and tested prior to releasing shop drawings for window production, to permit the opportunity to make design changes based on the performance of the field test mock-up.