A contemporary space where art, history, architecture and luxury travel collide.
The grain silo was the tallest building in Sub-Saharan Africa at 57m when it opened in August 1924 after three years of construction. Much like that initial construction, the redevelopment of the building has taken almost three years since breaking ground in May 2014.
The redevelopment had international vision but it is very much a local success story that has engaged a vast cast of characters and businesses creating jobs and pioneering engineering and architectural opportunities. A development of this nature must remain relatively fluid in order to deal with the numerous challenges discovered on site along the way. The experienced team has had to adapt and enhance the design as the project has evolved.
During the redevelopment, the building has grown to 65m and the external façade of the grain elevator has transformed into an intriguing modern tower through the incorporation of 82 pillowed glass windows carefully inserted into the geometry of The Silo Hotel. Zeitz MOCAA occupies the lower part of the grain elevator and the 42 grain storage silos.
A game changer for South African tourism
There are a further 20 pillowed glass windows on top of the grain silos themselves taking the total count of these colossal fixtures to 102. Each window protrudes over a metre, is roughly 5.5 metres tall and contains 56 triangular glass panels.
Looking through these windows is a unique experience – a compound eye gazing upon one of the most beautiful cities in the world. A modern lens that feels at times like being at the helm of the Millennium Falcon.
We caught up with Mark Noble (MN), Development Manager at the V&A Waterfront, Martin Lardner-Burke (MLB), Partner at Rick Brown Associates (the South African architects) as well as Arup (ARUP), the project engineers, to ask a few questions about the practical implementation of the radical design.
Do you see this a pioneering architectural endeavor for South Africa?
(MLB) Absolutely, in the sense that the building represents a major piece of recycling through reinvention. The pillowed glass facades have a metaphorical relationship with the building’s original function in that each window is shaped like half a grain kernel. They are also designed to enhance the purity of the concrete frame and express the ‘lantern in the harbour’ effect conceptualised by Thomas Heatherwick.
How did the V&A Waterfront go about turning Heatherwick Studio’s concept into a practical reality?
(MN) Through extensive workshops between Heatherwick Studio and Arup in London and Cape Town, a workable design solution was found. This included numerous workshops on the geometry of the actual frames as well as the quantity and shape of the windows. This design was then interpreted locally by WBHO (the builders) with the assistance of the facade sub- contractor.
Who manufactured the steel frames?
(MN) Through a tender process, a short list was drawn up of facade contractors capable of undertaking this complicated construction. Mazor were selected and all the units were manufactured locally in Killarney Gardens, Cape Town. Each window was then transported to site as a single unit, fully glazed, and craned into position.
To manufacture each unit precisely, Mazor constructed a jig which was used to accurately position each piece of steel and aluminium within a 1mm tolerance.
Are all the windows the same size?
(MN) No, most of the floors in The Silo Hotel are a different height. Floors six and seven are the same height, but floors eight, nine and ten are all different. The tallest windows are on the sixth and seventh floors which enabled the insertion of mezzanine levels into those two floors. There are actually five unique pillow shapes. The corner pillows above the silos each have 80 panels.
How did you deal with the challenges of light and temperature regulation?
(MN) The double glazed panels are designed with a high performance, soft coated, outer pane which prevents both heat gain in the summer and heat loss in the winter. This was manufactured by AGC in Belgium using the ‘float glass’ process (developed by Pilkington in 1959). The glass gains a lustrous finish and perfect flatness by floating it on a bath of molten tin in a chemically controlled atmosphere.
The glass sheets were then transported to South Africa where all the cutting, polishing and fabrication took place.
Due to the convex shape of the windows, cooling air streams may occur, particularly in the winter. Trench heaters will produce a countering upward air flow.
(ARUP) The high performance glass was selected to achieve specific solar performance in order to reduce solar gain as much as possible within the design intent. Interestingly, the pillowed geometry reduces solar gain into the rooms compared with conventional flat glass.
In what way has the building’s history and original structure and machinery been incorporated into the contemporary redesign?
(MLB) The museum is divided into existing found spaces and new pristine gallery spaces. Found spaces are left raw and true to the original building materials and structure while the new pristine white boxes are minimal in their design.
What were the main challenges that you faced during this process?
(MN) The geometry of the windows is incredibly complicated. Great effort was spent on finalising the geometry to optimise the “look” of the windows and then even more effort was spent on the manufacturing process. Each window was fabricated on a reverse jig which allowed each section of steel, glass and aluminium to be cut to an exact size and then held in place during the welding and fixing process.
(MLB) Re-purposing an industrial heritage building brings about a number of major challenges in the provision of services, waterproofing etc. If you add to this the sculpting out of a massive portion of the structure at the heart of the building to form the grain shaped atrium, while inserting a major new gallery and a boutique hotel, you begin to get a sense of the complexity of the task. The thought process required to deliver a building of this complexity has really resulted in some innovative solutions to some difficult challenges.
Comfort and design are not always the most sympathetic bedfellows. Much of The Silo Hotel development has been about finding a balance between contemporary industrial design and guest comfort and enjoyment.
Liz and the rest of The Royal Portfolio team place guest comfort and enjoyment at the heart of everything. The pillowed glass windows themselves have been a great example of these at times opposing ideals – reconciling spectacular design with guest comfort in terms of temperature, light and privacy.
The guest experience is paramount and this philosophy is deeply entrenched in our Purpose & Values.
Heatherwick’s initial vision for the grain elevator portion of the building did not contain any opening windows – a pleasing aesthetic but an impracticality for a luxury hotel. A compromise was reached where every room in the hotel would have access to fresh air by incorporating sliding doors and balconies into the centre of each of the four external walls.
Each bedroom is fitted with black-out blinds that unfurl automatically from the ceiling while each bathroom is fitted with sheer blinds allowing guests to enjoy the incredible views in privacy. Trench heaters, under floor heating and air conditioning ensure guests’ comfort through the seasons.
So there you have it. The inside scoop on one of the most intriguing aspects of the new hotel – as much a work of contemporary art as the remarkable collection in Zeitz MOCAA below.