A 4-Star Green Star rating represents the best practice in the South African context for designing and constructing buildings. And while this rating is important for the project as the sustainability credentials are confirmed by an independent certifier, the wider impact is even more important, and that is the collective effort of all stakeholders – the building owner, the professional team, the contractors and the occupiers to be part of the movement transforming the South African real estate sector towards a sector that is more sustainable and resilient.
“As part of our ongoing commitment to the Green Building Council of South Africa, and since we became gold-founding members in 2008, we have continued to press forward with sustainable developments. It pleases us that we have been able to add a new layer to the 30-year-old Merchant Place complex given our ongoing relationship with RMB and Eris Property Group. This adds to our vast record of more than 30 rated buildings,” explains Bob van Bebber, director at Boogertman + Partners Architects.
“Known as 8 Merchant Place (8MP), the building, in many aspects, is most definitely a new addition to the Merchant Place complex in that it adds a mixed-use service building to a corporate campus and has become the heart of the campus with ongoing day-to-day activities and events. It also makes a big impact visually for what is a very small building. In the way that it contrasts the very rectilinear existing built fabric of Merchant Place and the adjacent Investec head office, with a curvaceous and sinuous outer form that seems to have been poured into the left-over space between the two corporate giants of Sandton, while borrowing from the existing detail of the bird’s beak cornice line of Merchant Place,” adds Van Bebber.
Leading consulting engineering and infrastructure advisory firm Zutari also played a crucial role in bringing this three-storey building to fruition by providing civil, structural and wet services in addition to environmentally sustainable design (ESD) consulting.
“This is in line with the purpose the building serves, namely a wellness centre fitted with medical rooms, gym, educare centre, complementary retail and a rooftop entertainment area with a perimeter running track,” explains Yovka Raytcheva-Schaap, associate, ESD consulting and project management at Zutari.
The project is a showcase of the one-stop-shop solutions that Zutari prides itself on co-creating with its clients. “Having the civil, structural and wet services all provided internally by us allowed for efficient co-ordination between the disciplines and resolution of any clashes and issues before the construction information was issued,” highlights Zutari technical director, Mark Axelrod.
Zutari’s structural scope of work encompassed the design and supervision of the new building, including strengthening the existing columns and underpinning the foundations, while the civil scope comprised the stormwater design. “From a structural perspective, the project was complicated by the geometry of the new floor slabs, strengthening the existing structure and interfacing with the existing services,” he points out.
Calculations revealed that the load-carrying capacity of the existing columns and foundations in the basement was insufficient to support the additional load from the new building. Zutari therefore developed strengthening details for the existing columns using reinforcement concrete collars. This had to be carried out with minimal interference to the functioning of the building and vehicle movement along Bute Lane and in the basements.
Existing services in the basements such as water tanks could not be moved, which posed additional challenges. For the foundations, the underpinning piles were installed unconventionally to avoid existing services. As a result, strap beams were introduced to resolve the eccentric loads. The existing ground slab had a pond and landscaping that had to be removed to construct the new elevated ground level. This consisted of sleeper walls with a BONDEK® slab, which is a profile steel sheeting widely accepted by the building and construction industry for high efficiency and speed of construction. To ensure that the new load was less than that of the existing ground slab capacity, the existing no-fines concrete under the new building footprint was removed.
In terms of wet services, Zutari was appointed as a consultant for the internal hot and cold-water reticulation, internal soil and waste drainage reticulation and central hot water generating plant installation, explains Vincent Gieselbach, the wet services engineer.
The design was carried out to meet both Green Star and SANS10400XA requirements. Efficient sanitary fittings were installed throughout the building. Hot water is provided by means of a central hot water system with a heat pump. Comprehensive water metering is installed and connected to the Building Management System (BMS) for optimal water-use management.
Enhanced indoor environment quality was achieved by means of increased ventilation rates, glare-control elements, optimised external views and connection to nature, thermally comfortable spaces and the use of occupant-friendly materials and finishes. Dedicated exhaust risers within the tenancies ensure that air pollutants from printing machines, for example, are exhausted outwards.
The building’s optimal energy performance results from the selection of energy-efficient HVAC systems and lighting, as well as the rigorous commissioning and fine-tuning of all services. Where individually enclosed spaces are unoccupied for a period, the BMS automatically switches off electricity-consuming services.
Given the location of the building in the wider Merchant Place campus, 8MP makes use of centralised existing services and facilities such as a standby generator farm, backup chiller capacity and the wider-campus BMS and parking spaces, which would have had to be sourced independently for a conventional building.
“This arrangement makes the project unique from a future reuse of equipment and facilities perspective, which certainly contributes to the improved overall environmental performance of the building,” highlights Raytcheva-Schaap.
Waste management was handled in a responsible way during the construction of the building. An Operational Waste Management Plan was implemented by the project owner to ensure that, once the building was operational, waste generation is reduced and diverted from landfill by means of recycling and/or reuse.
The building also incorporates safety features aimed at limiting the spread of Covid-19 infections and similar viruses. For example, the main entrance of the building, as well as all entrances to the different tenancies, feature touchless doorways.
The drawings for the existing building were all completed on CAD. However, due to the geometric complexities of the new building, 3D modelling was vital for the success of the project. Together with Boogertman + Partners, Zutari drove the Building Information Modelling (BIM) collaboration on the project, ensuring all services were coordinated on one federated model.
“The benefits of 3D modelling were transferred to the contractor, as initially it was challenging to visualise the complex slab geometry,” adds Axelrod. Zutari assisted Trencon to install Naviswork Freedom, as well as demonstrating how to operate the model.
Project completion was originally planned for 20 January 2021. However, due to Covid-19 restrictions, the site stopped all work for ten weeks from March 2020, and the project was finally completed on 16 July 2021.
“The ESD credentials of the building, as well as the implemented occupant health and wellbeing features, are a testament to FirstRand’s commitment to environmental sustainability and providing best-in-class support services to its employees,” concludes Raytcheva-Schaap.
The chief operations officer for the Merchant Place Campus Real Estate Management Services, Vinod Naidoo, says that 8MP has added significant value to the campus experience and met FirstRand’s ambitions to develop environmentally sustainable workplaces for its employees.