The impressive extension, crowed by this innovation in technology and design, is due to open to shoppers in November this year, bringing even more diverse shopping variety to meet the ever-growing needs of Sandton City’s market and making the centre more shopper-friendly.

The magnificent dome atop the breathtaking new Protea Court is part of the super-regional shopping centre’s redevelopment and expansion project, which involves interior refurbishments and 30,000sqm of new retail space.

The R1.77 billion first phase of the Sandton City redevelopment is being undertaken by Liberty Properties on behalf of owners Liberty Group Ltd (75%) and Pareto Ltd (25%). Sandton City’s entire retail space, including the extension, will total 143,690sqm on completion of this phase. This will take the complex, which includes the hotel and office component, to a massive 215,000sqm.

“The expansion of Sandton City is set to further strengthen the centre’s position as one of Africa’s leading retail icons on the merit of both its exceptional retail offering and fresh, modern and bold design,” says Julie Hillary, General Manager Sandton Region, for Liberty Properties. “This includes embracing the best and latest materials, innovation, design and retail principles.”

The Protea Court roof has been created with a product called Texlon, which is made up of multiple layers of foil known as ethylene-tetra-fluoro-ethylene (ETFE), which is a modified polymer.

“Texlon is an innovative technology used worldwide but has been used for the first time in South Africa at Sandton City,” notes architect Tia Kanakakis from MDS Architecture. “It was selected as a suitable roofing material as it is lightweight and an environmentally-friendly climatic envelope”.

ETFE consists of pneumatic cushions restrained in aluminium extrusions, supported by a lightweight structure. The cushions are inflated with low pressure air to provide insulation and resist winds.

According to Kanakakis, the material translates the dynamic design intent for the structure while providing a suitable lightweight material for use over the centre when the remainder of the Sandton City master plan design is implemented.

“The ETFE material is unique in that it does not degrade under ultraviolet light or atmospheric pollution,” Kanakakis points out. “The material doesn’t harden, yellow or deteriorate. Furthermore, as the surface is very smooth and has anti-adhesive properties, the envelope self-cleanses in rain.”

Made by UK company Vector Foiltec, Texlon combines exceptional light transmission with high insulation. Each layer can incorporate different types of solar shading enabling the design to optimise the aesthetic and environmental performance of the building envelope.

“Incorporating ETFE into the design of the court has offered opportunities to control the amount of solar shading and to manipulate the visual transparency required of the roof design,” Kanakakis says. “These properties, coupled with the ETFE’s very low levels of embodied energy and outstanding environmental characteristics, result in an ecologically benign roof enclosure for the Protea Court.”

For Sandton City this means the increased “eco-nomic” operation of the centre – respectful of both the environment and energy costs.

Other advantages of the material which attracted Liberty to incorporating it into the design for the Sandton City extension is that Texlon isn’t a petrochemical derivative, it is recyclable and many components are fabricated from recycled materials.

“Besides the ETFE being new technology introduced through new construction methods in South Africa being used at Sandton City, the material has very long life, is highly energy efficient and comprises of environmentally-friendly technology," says Hilary. “This is in line with the sustainable principles Liberty Properties applies to property development”.