Diganta LTD

Point Supported Glass Façade System

It has been increasingly popular to attach the glass to the structure using fittings directly connected through holes in the glass. These fittings allow improved transparency and offer additional architectural opportunities in the detailing of these connections. Architects nowadays design structures with reduced or eliminated visual barriers between the outside and inside of buildings. This trend means that modern buildings today have fewer impediments to the outside view. The application of this Façade System allows for the realization of such structural designs.


The 1970s began the widespread use of aluminium extrusions for mullions. Aluminium offers a unique advantage as it can be easily extruded into nearly any shape required for design and aesthetic purposes. Today, the design complexity and shapes available are nearly limitless. Custom shapes can be designed and manufactured with relative ease.

Limitation: The modulus of elasticity of aluminium is about 1/3 that of steel. This translates to 3 times more deflection in aluminium mullions compared to stainless steel mullions.


Aluminium/Steel Mullions can also be in-filled/replaced by glass, which provide an architecturally pleasing building as well as being able to maximize on the benefits of day lighting. The resulting structure virtually disappears from view. This is achieved by eliminating all notions of structural support and devising a composite system in which the glass operates as a component of a working structure. However, parameters related to solar gain control such as thermal comfort and visual comfort are more difficult to control especially when using high-glazed curtain walls.


Deflection in mullions is controlled by different shapes and depth of curtain wall members. The depth of a curtain wall system is usually controlled by the area moment of inertia required to keep deflection limits within the specification. The area moment of inertia refers to the property of a shape that is used to predict its resistance to bending and deflection. Another way to limit deflection in a given section is to choose steel (which has a higher modulus of elasticity) instead of aluminium. The steel can resist much of the load at a lower cost or smaller depth.