Lighting in Design February-March 2016

costs. At the same time, the insulating effect of the ETFE roof supports the efficient thermal per- formance of the building, thus also contributing to energy conservation. The atrium roof Ethylene tetrafluoroethylene is a copolymer that was developed originally as an inert coating mate- rial for use in the aerospace industry. In building, it found applications initially in agricultural green- houses before being adopted in much more ambi- tious projects: the Eden Project in Cornwall, UK, in the late 1990s, the Allianz Arena in Munich for the 2006 Soccer World Cup and the Aquatics Centre, otherwise known as the ‘Water Cube’, for the 2008 Beijing Olympics demonstrated the architectural potential of ETFE. As a roofing material, ETFE has a number of significant advantages. - While the film has a high tensile strength which makes it structurally resistant, it also has a high elasticity. - It is significantly lighter in weight than glass while offering exceptional light transmission with 90% to 95% transparency. - It has a low surface friction coefficient, so it does not hold dust or dirt which simply washes off in the rain. - It does not discolour or degrade under exposure to ultraviolet light, environmental pollution or extremes of temperature – all plus points for a South African Highveld application. - It also has far better acoustic properties than a hard roof surface such as glass or metal. - And it can be recycled. The raw granulate is extruded into sheets, referred to as film, and these can be applied in single-layered form or in double- or triple-layered applications. In multi-layered applications dry air is incorporated at low pressure between the layers of film, creating inflated cushions that provide an effective measure of thermal insulation as well as increased structural stability against wind loads. Under typical loading conditions, ETFE cushions can range from 1.5 m to 3 m wide and up to almost 7 m in length. Additionally, a frit pattern can be incorporated on one or multiple layers to adjust the solar perfor- mance of the material to requirements, providing a further degree of controlled shading and protection against glare and internal heat gain. At the Multichoice building the transparent roof is supported by a shallow arched structure that is

fabricated in slender tubular steel elements and spans some 24 m – between the east and west wings of the building.The three-layered ETFE instal- lation incorporates a layer with a high-density print and the large free-form cushions of the material can be inflated or deflated to control light penetration and glare by adjusting the shading created by the printed layer. As an insulating membrane, the roof also limits heat build-up within the atrium space. It has the further benefit that, because it is transparent, it allows people working in the building to feel connected with the external environment – the movement of the sun, the changing weather and the changing seasons – which makes for a healthier workplace. Flexible ways of working dsgn design was appointed to design the interior of the building to reflect the Multichoice brand and corporate culture, to portray a progressive, forward- thinking multi-media company, considerate of its employees, and to provide for flexibility in working scenarios, recognising how the work environment is evolving, with technology in the forefront. Open plan office space is organised around the light-filled atrium. Along the atrium ‘street’ at ground level and overlooking this central volume, various pause areas and breakaway zones, casual clusters of seating and futuristic meeting pods where staff and visitors can interact animate the space. Bridges and stairs criss-cross the atrium at different angles and levels connecting the vari- ous departments. This planning approach creates a dynamic interior and provides for flexible ways of working, increasing the range of places where informal interactions, spontaneous conversations and a creative exchange of ideas can occur. The atrium also meets the client’s requirement for a place where large staff gatherings can be hosted for new product launches or other corporate announcements. Congruent with the concept of flexible ways of working, dsgn introduced organic shapes – in the customdesignedmeeting pods, for example, aswell as other furniture – and bright colour, which appeals to the senses and reflects the Multichoice identity, is used in accent walls, furnishings and rugs. The building is fully equipped with advanced information, telecommunications and media tech- nologies supporting 24/7 global connectivity and it provides a host of amenities for staff, including a gym on the fourth floor and a coffee shop which spills out into the atrium at ground level.

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LiD FEB/MAR 2016