A GREEN Connection
Developed by Attacq, the four-storey Nexus 1 is located on Magwa Crescent in Gauteng’s Waterfall City, and forms a part of the Nexus precinct, together with the Courtyard Hotel and two other office buildings positioned in a landscaped site on a shared basement. In February 2023, the new building was accredited with a 5-Star Green Star Office Design v1.1 rating by the Green Building Council South Africa (GBCSA), with further aims to achieve an As-Built rating and Net-Zero Carbon certification to demonstrate its intent on contributing to sustainability in the built environment.
visual appeal
With the whole Nexus precinct being designed by LYT Architecture, including two buildings still to come, the brief was to design a building with a distinctive architectural style, and in keeping with Attacq’s commitment to meeting a minimum 4-Star GBCSA Green Star rating. The building’s facade holds visual appeal through a multifaceted treatment, with the use of glass, precast concrete fins, and ventilated porcelain tiles in different shades of grey. These respond to the orientation of each elevation, adding interest while remaining aligned with the uncluttered visual language used throughout Waterfall City. The vertical elements create an impression of height, while the colour palette complements the neighbouring Courtyard Hotel.
The access to natural lighting available to Nexus 1’s central core and surrounding office space was maximised to achieve energy saving, at the same time promoting occupant wellbeing. There is an entertainment terrace on the third floor, with two fire escapes located within the central core of the building, leaving the rest of the space available for easy tenant sub-division.
Entrance to the building is from the road or the central piazza, which is accessible from all buildings on the square, with pedestrian and cycling routes connecting to nearby residential and commercial precincts. While all Waterfall City buildings are located close to public transport routes, cycling facilities are promoted, as this is the ultimate low-carbon commuter choice.
Best in class
A host of advanced features in the building deliver best-in-class environmental sustainability. Notably, the project achieved full points for the energy use credit, meaning that the base building has net-zero modelled emissions. Elri Syfert, Sustainable Building Consultant at Solid Green Consulting, says that this was achieved through passive and efficient design measures, and a solar PV system. “Due to the PV system, the peak electrical demand load on electricity infrastructure has been reduced by 34%,” she says.
The building’s lighting design ensures the use of artificial lighting with minimal energy consumption, as the energy use of 1.5W/m² per 100 Lux was set for the office lighting power densities. Given that gathering information is key to understanding and managing building systems, sub-metering of the major energy-consuming systems is in place. This is also the case when it comes to water consumption, with sub-metering present, and savings measures such as water-efficient fittings that limit the modelled occupant water usage to 0.56L/day/m².
As construction is an activity associated with a high level of greenhouse gas emissions, a project-specific environmental management plan was developed and implemented for the duration of construction, thus establishing guidelines to follow for minimal environmental impact. Likewise, a project-specific Waste Management Plan was developed and implemented to reduce the contribution of waste going to landfill. All of the selected gaseous and fire suppression systems and thermal insulants used for the development have an ozone depletion potential (ODP) of zero, to eliminate any contributions towards long-term damage of the earth’s stratospheric ozone layer.
The vertical elements in the building’s facade create an impression of height.
A world-class smart city
Such commitment to green practices is evident throughout the world-class smart city that is Waterfall City, which – for the eighth time in nine years – was named Best Mixed-use Development in South Africa last year at the International Property Awards. As part of Attacq’s environmental, social and governance (ESG) strategy, sustainability has been a key focus area for the group, with the vision to develop Waterfall City as a safe, sustainable, mixed-use city that provides a vibrant and healthy living environment. As Attacq’s former Chief Development Officer Giles Pendleton put it: “We believe that buildings should not be considered in isolation from their environments and communities, but rather complement and accentuate their surroundings. The rigorous focus on material selection, human comfort, air quality and human health features of our buildings rightly prioritises the most important asset of our buildings – people.”
A rendered image depicts the entrance and lobby of Nexus 1.
The Nexus 1 building sets a benchmark for sustainable premium office space, as it will be the first net-zero carbon level 1 building within Waterfall City. Syfert says that the features to ensure that the building qualifies for this rating will include the reduced demand gained through passive design measures and performance building simulations done early on in the project, energy-efficient equipment and appliances, and adding renewable energy to cover the remaining energy demand.
A total system size of 223kWp will produce an estimated power production of 379 900kWh/year. This will meet the building’s annual energy use in terms of heating (2 758kWh), cooling (130 159kWh), ventilation (85 779.1kWh), fixed lighting (88 337kWh), miscellaneous fans (37 024kWh) and hot water (3 184kWh).
The four-storey Nexus 1 is located on Magwa Crescent in Waterfall City, and forms a part of the Nexus precinct.
Maintaining a legacy
“For the As-Built submission, we need to ensure that future tenants adhere to the Green Star requirements relevant to the project,” says Syfert. “Solid Green has prepared a Green Guide, outlining these requirements, which must be given to future tenants and future fit-out teams to implement from the concept design phase.”
Most exciting, perhaps, is the fact that a building like Nexus 1 represents what is fast moving towards the acceptable ‘green standard’ – a far cry from where the industry stood a decade ago. Syfert comments on the exponential growth in the sector: “Where building green was a ‘nice-to-have’, it is becoming a ‘must-have’. In order to obtain international funding, ESG reporting is required, and that has had a huge impact, with third-party verification from an organisation like the GBCSA contributing significantly to a company’s ESG. Alongside South Africa’s commitment to the Paris Agreement, developers with large portfolios are also under pressure to design and build in a way that reduces carbon footprint.”
Along with growth in the industry, the costs of going green have been reduced, and the long-term benefits usually outweigh any price premium. This relates to both financial and environmental benefits. Syfert says that the Nexus 1 developers were able to reduce their carbon footprint along with the occupancy costs. And, as Lourens du Toit, Head of Sustainability, Infrastructure and Land at Attacq, explains: “We pursued a net-zero carbon level 1 certification to demonstrate our commitment to developing environmentally friendly and sustainable spaces for our clients, as well as a broader commitment to a sustainable built environment in general.”
There is little doubt that Gauteng’s Midrand is richer for the ethos that Waterfall City has brought in creating a green environment that benefits residents and businesses operating within the precinct. Nexus 1 paves a new way forward, with its enhanced approach to sustainable planning and development.
As Waterfall Management Company CEO Willie Vos says, “Winning the Best Mixed-use Development in South Africa award again reaffirms Waterfall City’s world-class status. Such recognition is an ongoing achievement that we and all our partners are very proud of. It has been an honour to watch this development evolve, and we have entered a new and exciting phase of our evolution as a world-class smart city. We will continue to showcase the excellence of Waterfall City and look forward to what the future holds.” Nexus 1 represents the start of this exciting future ahead.
