Factors Considered by Architecture Firms in The Use of Curtain Walls in Building Designs

Architecture firms committed to innovative designs go the extra mile to ensure unique, structurally sound, durable, and functional designs. The curtain wall is an example of how architecture firms help to keep commercial building designs fresh and functional.

The curtain wall is a structural system that covers the outside of the building structure. It is not essential for the structural integrity of the building. Instead, it can be considered a non-structural part of the design. So, why do architecture firms sometimes design buildings with curtain walls?

Aesthetic appeal is the obvious answer, but there is more to it. The curtain wall is made from lightweight materials. The purpose is to reduce the effect of weather elements on the building occupants. Glass is often used because it allows for natural light penetration deep into the interior of the building. With the façade not carrying the building’s structural load, it does not have to include all the structural strength components needed to carry the building load.

Architects consider various factors in choosing the types of curtain walls for commercial buildings. The three main systems used are:

  • Ladder
  • Stick
  • Unitised


It is a curtain wall system where mullions are used. These mullions can be screwed or snapped together. The system thus consists of pre-manufactured wall sections that can be put together at the construction site. The main advantage is a reduction in installation time. A disadvantage is a reduction in structural performance. Visible joints can reduce the aesthetic appeal of the curtain wall.


Architecture firms mostly use the stick system. Long pieces are installed. These pieces are referred to as sticks. The frame sections can be pre-manufactured, but the glass installation and glaze part take place at the construction site. The installation thus takes longer, but structural performance is improved.


The walls are manufactured in the factory, and are glazed and assembled in units. The units are installed on the building. Installation time is reduced, whilst quality control over each unit size and strength ensures good quality panels and structural integrity.

Design Factors

Architects consider various factors in the design of curtain walls to ensure the walls can handle the load imposed, while also keeping water or air from infiltrating the building structure. Some of these factors are briefly noted below.

The load imposed is transferred to the main building through the anchors, attaching the curtain wall to the building structure. The dead weight of the curtain wall must be considered. It consists of the mullions, structural parts of the curtain wall, infill material, and anchors. It can also include signage or sunscreen systems.

The curtain wall design must be done also with wind load in mind. The wind load is the force of the wind on the building. The curtain wall resists the wind pressure and thereby reduces the effect of wind on the building structure. The thermal load is an equally important consideration. The expansion and contraction of the curtain wall as the result of temperature changes must furthermore be considered. Architecture firms must also consider air and water infiltration factors.

As one of the experienced commercial and residential architecture firms in South Africa, we are able to provide you with building designs that include curtain walls. Give us a call to discuss your particular design requirements.

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