AECOM was appointed by Growthpoint Properties to provide a multidisciplinary service including structural, civil and geotechnical design, quantity surveying and construction supervision to the Exxaro Head Office, a world-class office building in Centurion, Gauteng. Completed in February 2019, this nine-story, 18,500m² corporate headquarters exemplifies sustainable design, innovative engineering and cutting-edge construction methods.
Overcoming challenges
The corporate headquarters are situated on a dolomite site with an Inherent Hazard Class of 8 and a highly variable rock profile that was once considered to be undevelopable. AECOM’s multidisciplinary team, including structural, civil and geotechnical experts, collaborated to design and implement groundbreaking solutions. AECOM’s final design saw the site excavated to the anticipated founding level, ranging from seven meter to one meter below Natural Ground Level (NGL). At five meters below the founding level, the bedrock was blasted, excavated and blended with an on-site chert residuum mix and recompacted. The entire footprint of the site was then dynamically compacted. In addition to a stringent water management system and a measurement and testing regime that allowed for the early prediction of propagating sinkholes, the project also included an innovative monitoring and warning system.
This project required the dedication of the full team – client, engineers, architects and contractors – working together to demonstrate what is truly possible cost-effectively in a challenging environment. The main building contract was finished within 18 months on time and under budget. The project’s success demonstrates AECOM’s ability to deliver exceptional results in challenging environments with a fully integrated team approach.
Recognition and achievements
The project achieved a six-star green rating from the Green Building Council South Africa (GBCSA) with a score of 76/76. In June 2020, the building received a silver-level WELL Core and Shell certification by the US-based International WELL Building Institute, the first WELL certification achieved on the African continent.
AECOM was actively involved in assisting the green consultant with its budget calculations on the different points strategies required to result in achieving four-, five- and six-Star Green Star and WELL ratings, respectively. The company’s expertise helped balance the complexities of the challenging dolomitic ground conditions site constraints and client aspirations to create a cost-effective and world-class development. Sustainable practices that were incorporated included stormwater attenuation and filtration.
Additionally, the project was recognized with multiple industry awards, including the SAPOA Property Development Awards 2021 for Innovative Excellence in the Corporate Office, Sustainability and Green and Overall Project categories. It also received the AfriSam Innovation Award for Sustainable Construction at the Construction World Best Projects Awards 2019 and a Highly Commended Award in the Consulting Engineering Category. Moreover, the project won the 2012 CESA Aon Engineering Excellence Award in the category of Projects Greater Than R250 million.