Report: Design of Glazing Facades for Building Construction

This report presents a detailed analysis of two design options for glazing facades in a multi-story building, focusing on material selection, structural integrity, and compliance with building codes. The report considers two options: Option A utilizes insulating glass units for maximum thermal insulation and minimized energy consumption, while Option B employs standard single-layer glass. Both options prioritize human safety by specifying heat-soaked toughened safety glass or heat-strengthened laminated glass. The design process involves calculating design wind pressures based on the building's location and applying these pressures to determine the required glass thickness for both strength and serviceability. The report also specifies the dimensions for mullions and transoms, considering steel rectangular hollow sections and their load-bearing capacities. The conclusion highlights the suitability of the selected glazing materials while acknowledging limitations due to varying interior conditions and the inclusion of a safety factor. References to relevant Australian standards are provided.

REPORT ON DESIGN OF THE GLAZING FACADES IN BUILDING
EXECUTIVE SUMMARY
The report hereinafter considers two design options in the selection, construction and installation
of the building facades to be used in a large complex storey building which shall accommodate
many occupants at a go. The glass material is therefore considered and it must support impact
human safety. Now, there are various building codes that have been used to ensure that design
conforms with the various standard requirements as provided by the Australian Construction
Building Authorities.
INTRODUCTION
Design of various building elements must be done in a manner that befits the original
requirements. In this case, the designer considers two options for selection in the construction
and installation of the best glazing façade for a building to be used to host several occupants at a
go. Now, in option A, a maximum thermal insulation and a minimized energy consumption are
to be attained. The glazing is to consist of insulating glass units. Therefore, for the purpose of
this assignment the outer glass is to be of the same thickness as the inner glass. While in option
B, Standard single layer glass is to be used. Importantly, however, for human impact safety, the
glass is required to be safety glass and therefore Heat Soak Tested Toughened Safety Glass or
Heat Strengthened Laminated glass is to be used. Notably, for both options, the glass weight may
be calculated using a density of 2500 kg/m3 but using the maximum manufacturing thickness
(tolerance is ±0.2 mm). For glass strength calculations the minimum manufacturing thickness is
to be used. Additionally, it is important to comprehend the region in which the building is seated
so as to make this improvements in that context.
DESIGN
1. In determining the design wind pressures (for both strength and serviceability) for the
building, the following assumptions are first made:
The region is identified as A4 in which the building is located (AS/NZS, 2002) hence:
The design wind pressures can be determined:
The projected areas are:
In North and south elevations:
A= 30x 75= 2250m2
And in the west and east elevations:
A= 75 x 50 = 3750 m2
Hence P= (0.5ῥ) V2des Cfig Cdyn where ῥ= 1.2kg/m3
Now, Vdes is fixed at 30m/s being the minimum value for this case
(this is due to the fact that the terrain is mostly category 3 and 4)
Cfig= Cp x Ka xKl x kp= 0.2x0.8x1.25x0.9= 0.18
And Cdyn= 1.0

Hence substituting:
P= 0.5x1.2x 302x 0.18 x 1.0 = 97.2
P = 100Pa
2. Using the appropriate greatest design wind pressures determined in 1, for Option A: the
minimum thickness of standard toughened glass to be used in the vision glazing to satisfy
both strength and serviceability (with same thickness assumed for both the inner and
outer glass):
This is fixed at 5mm based on the greatest pressure (Australia Standard, 2006)
(b) Now, we need to determine if 10 mm heat strengthened laminated glass to be used in
the vision glazing will be adequate for both strength and serviceability (by assuming the
same thickness for both the inner and outer glass).
As checked earlier, 10mm is adequate for this case.
3. Using the appropriate greatest design wind pressures, we have determined, for Option B:
(a) We can now determine the required thickness of the vision glass if it is to be
Toughened glass to satisfy both strength and serviceability.
-Required thickness of the vision glass, t, is found to be: t= 3.5mm
We check whether this is adequate:
The volume of the glass (assuming it completely covers the entire North, South, East and
West elevations hence:
Considering West and East elevations:
Volume= Axt = 3750x3.5x0.001= 13.125m3
Therefore, the weight W= mxg= 13.125x2500x9.81= 321.8kN
But the wind pressures, P = 100Pa, the resulting Wind force, F= P.A= 100x13.125=
131.25N
Suppose we double this to also satisfy serviceability hence 2x131.25= 262.5N
Therefore, the glass thickness has a greater structural integrity against failure due to wind
loads and internal pressures.
Now, consider the North and south elevations:
Volume= 2250x3.5x0.001= 7.875m3
The weight W= 7.875x2500x9.81= 193kN
Again t=3.5mm is okay since even if we double the loads, a safety factor still exists.
Hence the design is safe.

(b) And then we determine the required thickness of the vision glass (which is to be Heat
Strengthened Laminated Safety Glass to satisfy both strength and serviceability).
-let it be 4.5mm (this value is derived in a similar fashion as the above)
4. Next, using the design wind pressures we have determined earlier, the required
dimensions for both the mullions and transoms (depth of section and wall thickness) can
be specified but firstly, the following assumptions are made:
(a) Steel rectangular hollow sections (RHS) to be used for the mullions and transoms:
(i) The steel can be C350 or C450 grade. Refer to standard sections and design
capacities available on Blackboard.
(ii) The mullions and transoms sections are not more than 75 mm wide (in fact
this okay with the architect) and having a wall thickness of at least 3 mm.
We select steel grade: C450
Part Depth d (mm) Wall thickness, t (mm)
Mullion 125 3
Transom 140 4
CONCLUSION
From the foregoing, the above design results shows that the glazing material selected would
work appropriately as the building façade of choice. However, it should be noted that, due to the
ever-changing interior conditions, the selected material serviceability is limited to some extent.
Notably, the factor of safety has been included to cover a wide range of serviceability.
REFERENCES
AS/NZS. (2002). Structural Design Actions: Wind actions Part 2. Council of Standards
Australia.
Australian Standard. (2006). Glass in Buildings: Selection and Installation. Australia Council of
Standards.