- Category: PROJECTS
- Published on 30 September 2016
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By Fiona Ingham
Sandton’s city centre is being transformed with slick and cosmopolitan-looking high-risers going up, set to tickle the bellies of the overhanging clouds. One of these is Sasol’s new corporate head office.
The construction of Sandton City in the 1970s marked a pivotal change for the area, and when business owners fled the urban decay of the Johannesburg city centre in the 1980s, many of them relocated here. Although four major banks and mining houses are still headquartered downtown, the migration north has continued for decades. The Sandton Central commercial node, centred on Sandown and Sandhurst, boasts some of the best and most expensive commercial properties and offices in South Africa.
Billions are being poured into construction, with Sandton having the most office rentals in South Africa and laying claim to more than 10 000 businesses, including many powerful financial, banking, and consulting companies, as well as the Johannesburg Stock Exchange. The redevelopment of the old Village Walk mall on Rivonia Road into a mixed retail/residential offering and two high-rise office blocks is billed as a R2.5-billion investment.
Paragon Architects has played a major role in reshaping the area, having designed the Norton Rose Fulbright building at 15 Alice Lane, the 140 West Street commercial development, and the new Alexander Forbes building at 115 West Street, among others. Now, the Sasol building adds another notch to its belt.
South African Synthetic Oil Liquid
Worldwide, this NYSE-listed and JSE-listed energy and chemicals giant has more than 30 000 employees working in more than 36 countries. The 10-storey building spans almost 70 000m2 and will provide a workspace for 7 000 people. The building also comprises a vast seven basements for 3 000 cars. The estimated R2-billion new South African Synthetic Oil Liquid (Sasol) corporate headquarters is set to open in September.
The facade comprises reflective glass, which is designed to fit in with the look that characterises contemporary Sandton, yet needs to provide privacy for those inside. In addition, two large skylights allow natural light to fill the space. The building boasts a full-size gym, an art gallery, and a complete commercial kitchen on the level beneath the restaurant.
Once completed, the garden-like outdoor areas will include courtyards, braai facilities, a space for yoga classes, as well as indigenous and water-wise flora areas. Sasol has also provided a habitat to encourage indigenous birdlife. When Plumbing Africa visited the site, trees were being planted.
The build started in July 2014 according to Leon Tobias of Jazzman Plumbers, the plumbing contractor. “We were responsible for all the water, sewage, and grey water harvesting. Because the building is intended for Five-star Green Star rating, we used supplies approved by the green building council,” he says. Tobias says that Jazzman had a team of 44 workers on site for the build.
The parking will be accessed from Katherine Drive and the building itself will be accessed from basement parking via escalators, he says. On either side of the escalators, walls of water will shower down for the visitors and employees’ optic enjoyment. The water ‘landscaping’ is being done by Waterscapes that also designed the R2.2-million waterworks project for the new Alexander Forbes’ building at 115 West Street, as well as the Alice Lane Towers at Alice Lane to the tune of R1.2-million. Jazzman’s job is simply to provide a water point.
Full filtration plant
Tobias explains that there is a full filtration plant and transfer pump room in the P5 basement. Rainwater goes from the roof of the building via a rainwater storage tank located in the P2 basement to the filtration plant, where it is mixed with grey water from the building. The filtered water is then stored in a concrete reclaimed water tank ready for use in the urinals, toilet flushing and irrigation. Backup municipal water is also provided to the reclaimed water tank via a float controlled solenoid valve in the pump room, which ensures that there is always water available, even in the dry seasons. All major water consumption activities in the building are metered and are connected to the building management system.
In the sewerage plant, the sewage from the upper basements (being P1 to P4) flows to the sewerage lifting station where the sewage is pulped or macerated. It is then pumped up to the street level sewerage outlet.
For the internal pipework, copper tubing was used, with theft of the tubing again being an issue.
The hot water from the boilers is heated by a heat pump.
In the offices, the taps and soap dispensers are all electronic, says Tobias. Provision has been made for at least one male and one female restroom per floor, to be equipped with hand showers for those of different faiths and hygiene practices. The building is also equipped with four dedicated squat pans and disabled toilets, including a disabled toilet in the gym. Restrooms are designed with state-of-the-art fittings and materials. Each office floor also has two pause areas, which include kitchen facilities for staff.
Tobias says that the challenges faced when working on a project of this scale is usually the same: working on different parts of the project simultaneously and having to build under severe time pressure.
At the beginning of the process, the plumbing, fire, and rainwater consultants all meet and organise zones in the ceiling space. Each consultant needs to stick to their zone. This is the theory — it doesn’t work entirely in practice. “When someone moves out of their zone by 30mm, the services clash. Then, when this happens, you have to take your service around or under the other services. These clashes happen when so many suppliers are working under pressure to install their services. It is essential that each stick to their zones, because when the time comes to install the ceiling grid, it cannot be too low,” he says.
A lot still seemed to need doing before the opening day of 14 September; yet, Tobias is confident that ‘miracles’ can happen overnight — he says he’s seen it many time before. Final completion and the handing over of the building can take years though.
Water management strategy
An effective water management strategy can significantly reduce municipal water consumption in a building. Only a small portion of a building’s water supply needs to be potable. Major water demands, like irrigation as well as toilet and urinal flushing, can be met with harvested rainwater or recycled grey water.
The Sasol corporate offices design team investigated two core principles that form the foundation of a successful water management strategy.
Potable water demand reduction
Efficient fittings for occupant amenities.
Water-wise gardening for reducing irrigation water demand.
Sustainable non-potable water supply
Rainwater harvesting from roof surfaces.
Recycling of irrigation water oversupply.
Grey water recycling from showers and hand wash basins.
Water efficient fittings and landscaping
Potable water demand by occupants can be reduced by installing water efficient fittings for occupant amenities. This will also reduce water discharge into the sewerage system, placing less strain on the municipal infrastructure.
Table 1 shows the water consumption of regular fittings and efficient fittings.
Water consumption of regular fittings and efficient fittings
Using irrigation controls to reduce irrigation to landscapes during rainy seasons can greatly reduce irrigation water consumption.
By harvesting and storing rainwater from roof areas for use in toilet and urinal flushing, as well as landscape irrigation, water demand can be further reduced.
Water from showers and hand wash basins can also be recycled and is a viable strategy for a multistorey building with cyclist facilities, where the roof area compared to total floor area is quite small.
Source: Alchemy, Paragon Architects and PJ Carew Consulting.
The building envelope
Integral to both the energy and indoor environmental quality of the building, is the design of the building envelope. The glazing balances the solar control performance with the daylight availability. This is achieved through what is known as spectrally selective glazing: only 40% of the heat in the solar radiation spectrum is related to visible light. Spectrally selective glazing reflects a significant component of the non-visible wavelengths, while allowing in more visible light compared to conventional tinted or reflective glazing that is indiscriminant. This is enhanced through internal blinds, which occupants may drop and rotate according to situations of high solar gain or extreme glare.
Indoor environmental quality
The indoor environmental quality places emphasis on high quality building experience for occupants, thereby providing a pleasant working environment. It covers aspects such as air quality and indoor pollutants; thermal comfort; adequate lighting and glare control; access to daylight and views; and whether the sound levels in the building are comfortable for the users.
The building is divided by atriums, which supply natural daylight to much of the office spaces. The building is designed so that most of the office spaces have access to external views. Internal finishes will all have a low volatile organic compound content, which are healthier for building users. Fresh air contributes to a healthy work environment by providing a constant supply of oxygen replenishment and removing indoor pollutants. The building is designed for 10 litres per second per person of fresh air, which is a 100% improvement on regulatory needs. Energy savings are incorporated via daylight sensors and motions sensors, among others.
It is not possible to design the blinds out of the building. But the glass has been selected so that occupants should be able to raise or rotate the blinds into an open position to enjoy the views the building offers when there is no direct sunlight on the fenestration