Architect and Builder November/December 2018 | Page 74

LIGHT STEEL FRAME BUILDING CATEGORY WINNER
Gateway West, Mall of Africa
The construction of Gateway West at Waterfall Estate
is a landmark project, albeit small in tonnage terms. It
illustrates what can be achieved using Light Steel Frame
(LSF) Construction.
The spherically curved and twisted façade walls give
expression to the architect's design through light steel
framing, at a much lower cost than would have been
the case had reinforced concrete been used. The rapid
assembly and erection shaved weeks off the building
programme.
The steel frame provides a ventilated façade which
translates into thermal insulation to the office building
interior. The wall panels consist of (from the outside)
aluminium cladding, ETICS cladding (60mm thick), vapour
permeable membrane, 90mm LSF support structure,
Cavity Bat insulation, and Fire Stop gypsum board for
the internal lining. Key to the success of the project was
the meticulous 3-D design to facilitate integration of the
curved LSF framework, the window schedules and the
structural concrete.
LSF allowed the designer to create a unique and striking
building exterior like no other. The insulated LSF walling
provides excellent insulation which will save electricity for
heating and cooling over the design life of the building. It
was executed at much lower cost than alternatives and
is said to be maintenance free. It is a prominent reminder
of creative design on the Waterfall skyline. A comment
received from the USA sums it up – “in what galaxy is
this building?”
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This iconic building’s triple curve-shaped façade was
designed as a hybrid steel structure, with the round hollow
section frames as the main structural backbone and LSF
panelling to provide the cladding base for the ETIC system.
The curved exterior of this building provides an
architectural masterpiece. The imaginative façade panels
change shape in 3 ways; bowing, curving and twisting
downwards from the roof. Detailed engineering and
modelling of the main structural steel structure and light
steel frame panels was extremely complex. However,
this building demonstrates the versatility of combining
traditional steel construction methods with modern steel
building technology. No other building material could
create this magnificent ‘Gateway’ into South Africa’s
leading commercial development.
LSF was also used in interfacing the side façades with
windows exactly as per the architectural specifications,
while maintaining the engineering strength requirements.
Achieving this required real engineering balance.
The ETIC system provided a weather skin as well as
support for the seamless external aluminium envelope.
Client/Developer: Attacq Property Development
Architect: Aevitas
Structural Engineer: HAGE Engineers
Steelwork Contractor & Erector: Ohlhorst LBS
Cladding Manufacturer: Alania Building Systems
Cladding Contractor: Ohlhorst LBS
Main Contractor: Group 5
Steel Awards