Murray & Roberts Buildings started work on the new South African Ernst & Young headquarters in Sandton in June 2012 and is working to an extremely tight construction schedule that will see the eight-storey Ernst & Young block completed by the end of October 2013 and the 14 storey tenanted office block, currently dubbed the Eris Tower, built by January 2014.
The prestigious new development, located at 102 Rivonia Road, is being developed by Eris Property Group. Ernst & Young, which provides assurance, tax, transaction and advisory services to companies and governments, has said the move will place the professional services firm at the centre of South Africa’s economic hub — the Sandton central business district. In addition, proximity to the Sandton Gautrain station provides easy access to OR Tambo International, an increasingly important consideration as the firm’s African business grows.
The built footprint will be 98 800 square metres and the development rests on eight storeys of basement parking including service areas, cold rooms, electrical plant rooms and water storage tanks. There will be a total of 1 150 staff parking bays, with provision for 100 visitor parking bays in the Ernst & Young block, with 544 staff and 29 visitor parking bays for the Eris Tower.
The building design has already achieved early recognition at the World Architecture Festival held in October 2012 in Singapore, where the project was shortlisted for an award in the Future Commercial Office category.
Boogertman + Partners are the architects on this development and have designed the building to comprise three elements — the eight storey building with an active atrium space animated by transecting stair and bridge links, the 14 storey office tower connected by a four storey high bridge that allows for future versatility and a two storey podium on which the buildings rests, further enhancing the visibility and legibility of the building. The podium forms part of the eight storey parking basement and forms the ground plane of the development accommodating the main entrances to both buildings. The ground floor of the Ernst & Young building includes a staff restaurant and a client hospitality area, both with external access to views.
Vehicle and pedestrian access onto the site is controlled within the boundaries of this podium, with separate vehicle entrances for the office buildings and their services. A grand sweeping staircase off Rivonia Road creates a seamless transition for pedestrians from street level to the podium. This is augmented by a collocated lift from street level up on to the podium.
The variable nature of the internal functions of the building manifest themselves as floating floor planes that create overhangs and protrusions, further enhancing the organic relationship between the façade and the horizontal flow of the spaces. The atrium staircases encourage people to circulate around the edge of the atrium and, with the bridges, promote internal communication and interaction among the occupants.
The façade, with convex and concave curves, will be constructed from a unitised performance glass with a light tint, in a double glazed unit which will be complemented by vertical fins, rotated at 30 degrees, to control natural light into the open office environment. The exterior of the basement area will be finished with a similar aluminium screen, providing natural light and ventilation to the upper two floors.
The main meeting rooms in both the Ernst & Young block and the Eris tower are on the seventh floors, offering excellent views from elevated balconies over the southern part of Sandton and the Inanda polo fields. The meeting rooms are connected to the main kitchen.
“This design is a first for the South African environment,” Bob van Bebber, director at Boogertman + Partners, says. “It is significantly different from any other building in the area and will certainly become a local landmark.”
Interior design has been undertaken by Adrian Davidson of Savile Row and will be characterised by a natural palette with polished concrete floors and some natural timbers to complement the loose fit open plan interiors with activity-based desking solutions. The design includes meeting and breakaway areas.
4-star green rating
Among several elements designed to collectively achieve a 4-star green rating, the building will make the most of innovative opportunities to harness natural light and ventilation, and to conserve energy. Alison Groves of WSP Consulting Engineers, responsible for the green aspects of the development, says pre-commissioning, commissioning and quality monitoring will be undertaken for mechanical, electrical, hydraulic and fire services in accordance with the correct Chartered Institute of British Engineers codes. This provides for a continuous process of checks and balances throughout the construction process, while final responsibility lies with the independent commissioning agent, Aurecon.
The building project is also being guided by an environmental management plan to ensure that best practices in environment, health and safety are applied.
“The building’s fully glazed façade will provide excellent ingress of daylight, which is linked to employee wellbeing,” says Groves. “At the same time, the glass will restrict radiant heat gain into the building and the problem of direct glare will be mitigated by the vertical fins. Sixty percent of the floor area will allow external views to the outside, enabling office personnel to look out of the windows and maintain a refreshing connection with the outdoors. In addition, the external glass has been modelled together with the HVAC system, with a primary focus on maintaining thermal comfort.”
All paint, adhesives, sealants and carpeting used in the indoor environment will have low VOC (Volatile Organic Compounds) content to mitigate the impact of internal pollutants.
There will be no geysers in this building — instead heat pumps have been planned. Electricity consumption will be heavily metered in regard to items that use 100 kVA and over, which will assist the building manager to monitor how the lighting is performing. The metering capability will provide accurate information for reporting purposes and draw attention to areas where user behaviour needs to be altered to reduce energy consumption. Occupancy sensors will also be introduced.
“We want to achieve less than 2 watts per metre square per 100 lux – a measurement of the efficiency of the light versus the energy it consumes,” says Groves. “The idea is to produce effective light at low wattage, which is a good benchmark of lighting energy in a building.”
Water usage throughout the building will also be metred as part of the Building Management System, which will also allow for early leak detection and any other anomalous use. Most water savings will be achieved by using environmentally friendly sanitation fittings — including low flow taps and showers and dual flush toilets. It is likely that semi-waterless hybrid urinals will be deployed, so that users need not flush the urinal every time it is used. Instead an automatic flush takes place twice a day. In addition, the project has provided for a 38 cubic metre storm water attenuation facility that will be fed to storage tanks, which in turn will supply the necessary water to flush toilets and urinals.
The building design has avoided any refrigeration that uses HCFCs for chillers, heat pumps and fire suppression systems, as well as in insulation materials.
Construction materials have been carefully chosen to reduce embodied carbon in the building, for instance, by reducing the cement content of the concrete by replacing it with fly ash or slagment. A 25% fly ash replacement reduces the carbon dioxide (CO2) content to 0.62 kg of CO2 per kilogram. Rebar steel with a high recycled content is being used in favour of virgin steel, which has 2.75 kg of CO2 per kg, compared to the 0.43 kg of CO2 per kilogram of recycled steel. Formwork and any similar installations will be built with sustainable timber.
The professional team is aiming for 20% of all permanently installed materials to be sourced from within 400 km of the building site.
Fast track building
Toni Flavio, director – projects at Murray & Roberts Buildings, says the single biggest challenge presented by this project is the short construction time that has required his team to work to a very fast track programme.
“The site logistics presents another challenge for the construction team,” he comments. “Very little lay down area is available on site for plant and materials. The construction team has to plan its logistics very carefully to avoid having excess materials delivered to an already congested site.
“In approximately half of the foundations, we encountered hard rock that had to be removed by blasting, and this put the programme under added pressure. As the excavation ramp was removed, the bulk of the excavated material was removed by a crane.”
Four Liebherr tower cranes are being deployed during construction — two 154 ECH cranes with 65 metre jibs and two number 132 ECH units with 50 metre jibs. The tower cranes have been strategically positioned to allow maximum cover, while not getting in each other’s way. Two tower cranes are positioned at the bottom of the excavation and two are located at ground level, outside of the building footprint.
To meet the requirements of this fast track project, Murray & Roberts Buildings will deploy more than 1 000 personnel, sub-contractors and labourers on site at peak. Construction is being accomplished by the primary use of post-tensioned slabs made of early strength concrete, formed by the PeriSkydeck formwork system.
By completion, the construction project will have used approximately 39 000 cubic metres of concrete, two million bricks, 6 000 tons of rebar and 98 000 square metres of formwork.
To date, Murray & Roberts Buildings has recorded zero Lost Time Injuries, which Flavio attributes to a sustained and intense focus on safe behaviours, underpinned by the Murray & Roberts safety philosophy, STOP.THINK.ACT.24/7. This approach emphasises the importance of taking action to correct unsafe conditions and behaviour, as well as recognising positive behaviour, while “24/7” highlights the need to be safety-aware at all times, both at work and after hours.