ON SITE dhk
The ground floor façade is set back , so that the three office levels above appear to float .
Basson informs that treated effluent is used to flush toilets , as well as for irrigation and cooling of the HVAC . The engineer says that the civils scope for the project was “ fairly minimal ” but nevertheless , he describes what it entailed : “ It involved bulk earthworks and subsoils , and we are also building an access road for this site and the site alongside it , and a ramp into the basement .” The entire Century City development is built on what was once a wetland , with very wet underfoot conditions owing to the high water table . This posed a challenge when it came to the earthworks . “ The two buildings are at different levels ,” the expert explains and adds that this difference was about a metre in depth . This variance created water seepage in the lower basement excavation , which then required dewatering . “ What we did was make a pioneer layer of large rocks and stones , with the maximum diameter measuring 100mm . Franki ’ s piling rigs were able to move on that surface , putting in the piles and lateral support for the building ,” he explains . Franki ’ s geotechnical works started at the end of November 2016 with the installation of a three-metre cantilever lateral support wall that consisted of 215 No . 500mm diameter CFA soldier
16 - CEC April 2018
piles and a gross 788m 2 of gunnite . The foundation piling commenced in mid-January 2017 and consisted of 513 No . 520mm diameter pre-drilled Franki piles , which were completed on 17 March 2017 . The end of January 2017 saw the completion of the lateral support piles , with gunnite completed on 24 February 2017 . “ All stormwater from the site are diverted back into the Century City canal system as per the Century City : Sustainable Urban Drainage System Evaluation & Master Plan ,” Basson explains . “ The water goes into a settling tank where the silt settles . The water then flows into another tank before being pumped back into the stormwater system . The good thing about this system is that only the overflow goes back into the municipal grid / network . It ’ s all contained within the canal system and doesn ’ t run out to sea .”
Architecture
The buildings are each split into two wings , with a central core and full height atrium bringing light into the centre of the expansive floorplates . Discovery ’ s new regional offices will be in the one building , while the other building , which is ideally suited for a large corporate , is being designed to be flexible and if necessary , could be subdivided to accommodate smaller users , says Rabie director , Colin Anderson .
Each building is set on a green podium with a sunken amphitheatre , creating an active public space , with shared basement parking below . The buildings actively engage with both Sable Road and Bridgeways , as well as with each other and the new developments planned for either side of the site . Both enjoy high visibility as well as panoramic views towards Table Mountain and Table Bay . The twin buildings are designed as a series of shifting volumes along the linear site . The ground floor façade is set back , so that the three office levels above appear to float . Two office levels are enclosed in a vertically articulated façade with recessed glazing , creating a delicate veil that serves as passive solar control . Within this layered envelope , protected walkways and terraces have been created to the north and south , capitalising on the differing views and seasonal changes . A further office floor takes the form of a fully glazed crystalline white box that floats on a shifted axis . This building form is reversed on each wing of each building , creating dynamic arrangement along the length of the site . dhk is responsible for the full architectural services , having previously designed the Bridge Park office building for Rabie in the same precinct in Century City . In addition