Architect and Builder Dec 2017 / Jan 2018 | Page 45

the Silos, the organic rounded shape of a single
kernel of the corn recovered from the original
building was digitally scanned and scaled up to
fill the 27m high volume and then translated into
thousands of coordinates, each defining a point
within the silo’s tubes. Mapped out physically with
nails, the concrete tubes, only 170mm thick, were
then lined with inner sleeves of new reinforced
concrete, essentially building a new building inside
the old one. The new concrete sleeves created
a stable composite structure 420mm thick and
provided a cutting guide for removing portions
of the old silos.
The existing tubes were pared back to reveal
the curved geometries of the 4,600m 3 atrium. The
cut edges were polished to give a mirrored finish
that contrasts with the building’s rough concrete
aggregate. Each of the carved tubes was capped
with a 6m diameter panel of laminated glass that
brings daylight into the atrium. The glass carries a
ceramic fri t pattern specially commissioned from
the West African artist, El Loko.
As well as mitigating heat from daylight, the frits
create a safe, walkable surface for the sculpture
garden at the rooftop level. The remaining internal
tubes were removed to make space for the 80
Zeitz Mocaa
gallery spaces providing 6,000sqm of exhibition
space. Underground tunnels surrounding the
atrium have also been adapted for artists to
create site-specific works. The proportions of the
upper half of the tower portion of the silo complex
made it unsuitable for exhibition space. The design
team reconceived this structure as an illuminated
beacon, which now houses the Silo Hotel.
Façade
The exterior of the building was altered with 2
major changes. Firstly, the magnolia paint was
stripped away to reveal the original concrete of
the silos, with all of the character of the original
construction techniques and the particular patina
created by years of weathering and repairs.
Secondly, the original windows were removed
and replaced with larger ‘pillowed’ multifaceted
windows on top of the silos.
When considering how to bring light into a
previously enclosed, dark space, the architects
were inspired by the bulging glazed texture of a
Venetian lamp. Arup followed a 24-hour lighting
philosophy for the initial lighting study, developing
a holistic lighting solution for the atrium space that
carefully balanced and combined daylight and
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