Stepping up to NET ZERO
Introduced in 2017, GBCSA’s Net Zero rating tool supports the global decarbonisation goal of achieving net zero carbon for all new buildings by 2030 and all existing buildings by 2050. It applies to new buildings, existing buildings and tenancies within these buildings, awarding certification to projects that go beyond partial reductions to achieve full neutrality – or even positive impact – in carbon, water, ecology and waste.
MEET SOME OF OUR NET ZERO HEROES
Accredited Professional: André Harms, Sustainability Engineer and Director, Ecolution Consulting
Q: Which of your net zero-accredited projects stand out most for you, and why?
AH: All of our net zero projects stand out for their own reasons. However, Two Dam Sustainable, ab responsibly operated trout farm with accommodation near Montagu in the Western Cape is one I’d choose to highlight. It was certified as Net Zero Carbon Level 2 (operational energy and measured) in 2017 as one of the first four net zero pilot projects in South Africa. The farm is holistically committed to sustainability and runs off-grid –almost entirely off renewable energy. More recently, the Hout Bay Roads Depot project for the City of Cape Town has just achieved a Net Zero Carbon Level 1 (modelled) certification. An effective passive design bolstered with a well-integrated renewable energy system, this project will produce more energy than its base building systems will consume.
Q: How did you integrate renewable energy systems into your buildings – did you face any challenges?
AH: When attempting to push the envelope, like we did for Two Dam Sustainable, there will always be some challenges. The project’s off-grid hybrid renewable energy system, despite being fairly small scale and low budget, managed to robustly integrate a micro pelton wheel hydro turbine, ground- and rooftop-mounted PV arrays, battery storage and back-up generators. The remoteness of the farm and the fairly harsh setting of the Klein Karoo had to be worked around. We also had to ensure the renewable energy systems were optimised to provide power and other benefits, such as solar panels providing shading or water from the turbine being used for farming.
André Harms spent over a year in Antarctica working at the South African Antarctic base as the team leader and head engineer. It was there that his passion for the environment was brought face to face with the critical situation we are facing on our planet. He returned to South Africa and founded Ecolution Consulting in 2011. Since then, André has dedicated his career to greening buildings (and now neighbourhoods) through his commitment to sustainable building design and operations. www.ecolution.co.za
Accredited Professional: Linus Naik, Managing Director, Green Gap Consulting
Q: Which of your Net Zero-accredited projects stand out most for you, and why?
LN: Dsm-Firmenich South Africa’s Net Zero Waste (Level 2) was a project that was conceived and initiated in 2022, and finally came through in 2025. This seminal piece of work has reshaped the Net Zero Waste – Level 2 standard in South Africa and paved the way for other net zero waste projects before it, and the many more to come. In addition, it has challenged the criteria of Net Positive Waste – Level 2, and hopes to be the first measured project that receives this certification – hopefully soon!
Q: What role did collaboration with other stakeholders play in achieving your sustainability goals?
LN: Deep collaboration was crucial to the project’s success. The site undertook massive efforts with the on-site waste management company, which itself had multiple stakeholders managing solutions for diverting waste from landfill. On the other side, the green building consulting team reached out for subject matter experts to get the project over the line. This project is a testament to SDG 17, partnering to achieve sustainability goals.
Linus Naik is a seasoned leader and environmentalist at heart and in practice. As Managing Director of sustainability consultancy Green Gap, and with over a decade at Don’t Waste, he has led initiatives in sustainability awareness, recycling practices and software and business development. Linus also serves as director of the Zero Waste Foundation, promoting waste minimisation, education and environmental conservation. www.greengapconsulting.com
Accredited Professional: Chilufya Lombe, Partner, Solid Green Consulting
Q: Which of your Net Zero-accredited projects stand out most for you, and why?
CL: 7 Parks Boulevard (Ikusasa), Oxford Parks, really stands out because it demonstrates high sustainability ambition and delivery in a challenging timeline. Having achieved a 6-Star Green Star Office V1.1 Design certification and later, an As Built rating in May 2024, it is targeting Net Zero Level 1 certification, meaning its mission is not just design, but also operational carbon performance. With 421 solar panels producing about 385 500kWh annually, what makes it special is that energy efficiency was embedded from the earliest design stages. The building integrates passive design and high flexibility: open floor plates, large span square grid, strong facade design (vertical fins, sun control, automated blinds), underground parking to prioritise pedestrian experience and clear daylight access, all of which reduce reliance on energy and make operations more efficient.
Q: How did occupant engagement contribute towards sustaining net zero performance over time?
CL: Occupants are key. At Ikusasa, features like occupancy sensors, sub-metering and real-time monitoring make performance visible and help people adjust their behaviour. The building also gives tenants great daylight, fresh air and comfort, so sustainable choices feel natural rather than forced. The building’s layout (public-interface spaces on the ground floor, open floor plates, flexible spaces) supports occupants having a say in how they use the space, and encourages behaviour (walking, non-motorised transport, shared usage) that reduces environmental load.
Chilufya Lombe is an experienced electro-mechanical engineer with a strong background in sustainability-focused design and compliance modelling. Specialising in Green Star project management, he excels in detailed modelling of building systems to optimise energy performance. Using advanced simulation tools like DesignBuilder and EnergyPlus, Chilufya has successfully enhanced building energy efficiency while guiding project teams towards sustainable solutions and away from conventional building practices. www.solidgreen.co.za
Accredited Professional: Francois Retief, Director, Sow & Reap Green Building Solutions
Q: Which of your Net Zero-accredited projects stand out most, and why?
FR: Bracken Nature Reserve (Net Zero Carbon Level 2) in Brackenfell South, Cape Town – this project was really great as we focused on good passive design and thermal comfort as opposed to high-tech solutions. Liberty 2 Degrees’ retail portfolio projects (Net Zero Waste) really opened our eyes to what leadership in waste management looks like, and just how much can be done at scale.
Q: How did you integrate renewable energy systems into your buildings, and were there any challenges in doing so?
FR: On Bracken Nature Reserve, in order to ensure that onsite solar would be sufficient to get us to net zero, we aimed to get the building as efficient as possible. We used comfort simulations to prove that no air -conditioning was needed, thanks to great passive design. Then we applied highly efficient hydronic underfloor heating to ensure winter comfort. This significantly reduced load was then met by a grid-tied solar PV array.
Francois Retief thrives on collaborating with others to create healthy, sustainable spaces and communities. A mechanical engineer by training, he specialises in developing practical sustainability strategies for the built environment. Francois is the founder of Sow & Reap Green Building Solutions, a consultancy that focuses on sustainability advisory services and building simulations.
www.sowandreap.co.za
Accredited Professional: Alison Groves, Director (Discipline Lead): Built Ecology, WSP
Q: Which of your Net Zero-accredited projects stand out most for you, and why?
AG: When we talk about net zero, the conversation often defaults to carbon emissions. But at Scania’s expanded site in Aeroton, South Africa, the spotlight shifts to a less celebrated, but equally critical dimension: net zero waste. Scania’s recent redevelopment involved the demolition of existing buildings, including a training centre and warehouses, to make way for a significantly larger assembly plant. The buildings were soft stripped, with precision-doors, windows, ceilings, sanitary ware, AC units and lighting salvaged and sent to secondhand dealers for resale. One warehouse was fully dismantled and rebuilt at the demolition contractor’s own property, extending the life of the structure, and avoiding landfill. The concrete platform was crushed on-site and reused asb aggregate for the new extended platform. This eliminated the need for transporting waste off-site and sourcing new materials-cutting both emissions and costs.
Q: What role did collaboration with other stakeholders play in achieving your sustainability goals?
AG: The civils and demolition contractor, Pentacon Civils, played a pivotal role in achieving net zero waste. The process required meticulous record-keeping and documentation – an effort that was supported by a committed client, Redefine Properties, who prioritised reducing both embodied and operational carbon emissions. The main contractor, JT Sons, continued this ethos by reusing rubble for on-site backfill or relocating it for cut and fill on another site in Gauteng. On-site crushing of concrete and bricks further minimised transportation emissions and costs. The resale value of salvaged materials helped subsidise the civils and demolition contract.
Alison Groves is a sustainability consultant and Discipline Lead: Built Ecology at WSP in Africa, where she’s worked since 2008. Alison now serves in WSP’s Global Net Zero Buildings and Future Ready think tanks, which look at strategic planning and design methodology in WSP services – striving for net zero, building resilience, and addressing climate change. Passionate about passive design and occupant well-being, Alison has been involved with numerous net zero projects that have been certified or submitted to GBCSA. www.wsp.com
