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CONSTRUCTION WORLD
MARCH
2015
STEEL CONSTRUCTION
Following a discussion with the local residents’ group,
a design evolved that comprised a raised platform at
street level that included parking but was expressed as a
planted volume. Most of the plants, especially the trees
were pre-grown so that once they were planted during October 2013,
they had reached some level of maturity. They included: Acacia
xanthophloea, Celtis africana, Viburnum sinesis and Ficus microcarpa.
Access to the street was to be welcoming.
Sitting atop the platform were the offices themselves, that were
heavily screened to the east and west with deep overhanging sun
screens on the north.
Steelwork forms
The steelwork forms and integral part of the design and the engineers
developed a language that was as elegant as possible. The columns
are 24 m long in a single length and from the 5
th
floor to roof they
taper to 250 mm from 500 mm. There are 12 columns externally and
16 internally.
The sunscreens were designed from a series of sun studies
executed by the mechanical engineer and internally the orientation of
the blades directs your gaze to the treed residential suburbs beyond.
Revised fire regulations required an extra staircase and this was
included in the architectural design.
Glazing
The glazing formed an integral part of the design and included the
following glazing specifications: AGC: double glazed Stopray clearvi-
sion 50T, spandrels with clear glass, double glazed back painted unit
and 3,85 m high ground floor vision panels. The biggest unitised glass
panels are 4,5 m x 1,4 m.
This office building is located on Jellicoe Avenue close to the
corner with Oxford Road. It is essentially on the border with Dunkeld,
which is a residential area. There was close co-operation with the local
residents and this was taken into account when designing the five
storey, 10 000 m
2
building.
The simplicity of the steel structure supports the large over sailing
concrete roof while the monolithic nature of the pristine white north
wall that floats above the ground with the help of the steel structure
behind stands in contrast to the fineness and delicacy of the steel
louvres on the east, west and north that takes grates care in displaying
its textured, soft nature. The basement also enters the mix to create a
green, textured podium for the structure to occupy.
Why steel was chosen
For the columns, tubular steel was chosen to keep the structure as
slender as possible (due to the stiff nature of tubular steel) while
maintaining a smooth finish in and to achieve an automotive metallic
finish. The columns were also finished off by adding a tapered section
at the top which was formed by rolling flat steel sheets.
The columns on the north, east and west elevations were five
storeys high, so steelwork was chosen for ease of construction as
these columns were going to
be very difficult to construct
in shuttered concrete over
that height. Tubular sec-
tions where chosen for their
bending properties in both
directions
primarily,
and
also for their elegance. They
allowed for the choice of
the elegant taper at the top of
the columns.
The
steelwork
frame
element hiding inside the
northern façade was chosen
to be constructed from steel-
work for the same reason of
build-ability.
The framing structure
for the brickwork substrate
behind the tiles would have
been very difficult to construct
in shuttered concrete as an
element on its own, which only
interacts with the building at the fifth floor. The louvres that shade the
building on the east, west and north elevations were manufactured
from large flat steel sheets, lasercut to form interlocking louvre blades
which come together to create a ripple pattern
Steelwork on this project
The slenderness and proportion of the tapered tubular steel columns
give the building and elegant aesthetic that sets is apart from its neigh-
bours. The ripple that is created by the louvre blades add another
level of detail that finishes off the overall concept. The fineness of the
steel elements work together to create a truly special building.
Sustainability considerations
Passive design principles were considered during the design process
and the steel louvres form a major part in the east/west and north
shading of office areas. The louvred profiles needed to be designed
in such a manner that they could be fabricated in panel sections
and easily erected on site with no welding required. The louvre blades
were designed to be profiled and cut from single sheets by interlocking
the faces in order to achieve minimal wastage and maintaining the
integrity of the texture.
Challenges and solutions
The challenge was always the tight programmne. OmniStruct did a
fantastic job on the steelwork’s quality considering the time implica-
tions. Another challenge was to make the connections elegant and
pleasing to the eye: designing with an appreciation for fabrication and
transportation while keeping an eye on the end product so as not to
defer the connection away from the original concept of ‘beautiful’.
>
BEAUTIFUL
STEEL
Paragon Architects was approached by Investec during 2011 to
propose a design to accommodate amongst other tenants, the law
firm Fluxmans. In keeping with the mores of Investec and the tenant, a
classical architectural approach was adopted, although the language
was not that of classical architecture.