
The road to net-zero waste is a journey, not a once-off event.
With most major metropolitan areas in South Africa expected to reach the end of their landfill capacity within the next ten years, stakeholders and businesses are urgently looking to minimise the amount of waste sent to landfill.
How can this be achieved?
It requires an iterative approach and continual improvements by businesses using net-zero waste principles. Green Gap Consulting helps companies to navigate the building requirements for effective waste management and achieving net-zero goals and certifications.
Melissa van Rensburg, Senior Consultant at Green Gap Consulting, advises on how to achieve net-zero waste.
Net Zero pathways
Net-zero waste is a best practice approach that focuses on reducing, reusing and recovering waste, following the waste hierarchy and preferred pathways. The Green Building Council of South Africa (GBCSA) has outlined two levels for which net-zero waste can be achieved.
The first level focuses on diverting all construction waste from landfills during new builds or major refurbishments, while the second level addresses operational waste generated by buildings. There are preferred pathways to guide this process and support companies on their net-zero waste journey (see Figure 1).
Figure 1: Net-zero pathways advise on best practice for achieving a Net Zero or Net Positive Waste status.
On-site activities
The first step is on-site efficiency, involving the reduction and reuse of waste on site. This critical initial step can be implemented by:
- Eliminating problematic packaging or waste materials.
- Adopting green procurement practices.
- Substituting materials.
- Reusing resources.
- Engaging with suppliers.
The second step is on-site recovery, which entails sorting and separating recyclables to maximise recovery and minimise contamination, with a minimum of 70% diversion and separation of waste required on site.
Once on-site efficiency has been maximised, only then should the third step be explored, which involves off-site treatment through recycling and recovery facilities. Net-zero waste acknowledges that diverting all waste from landfill may not always be the most environmentally friendly option, so the final step, waste offsets, allows a small percentage to be offset through verified carbon trading schemes if necessary.
Designing for net-zero waste
So what does net-zero waste mean from a design perspective? It is important for green building professionals to design with sustainability in mind.
From a design standpoint, achieving net-zero waste requires buildings to be constructed with adequate space for on-site separation and recovery of waste materials, ensuring that waste is minimised right from the source.
Historical context
In South Africa, waste management has historically fallen behind infrastructure development due to a focus on the linear economy model. This emphasised resource extraction and expansion over waste management.
The policy “The minimum requirements for safe disposal of waste to landfill” concentrated solely on safe landfill disposal rather than comprehensive waste management. As a result, infrastructure often lacked space for waste sorting and recycling, creating a persistent gap between development and effective waste management.
New focus
Currently, more space is being allocated for waste management. The GBCSA is currently updating the New Build Green Star Tool V2 under the responsible construction and waste management credits to ensure that adequate space is dedicated to waste.
The tool includes best practice guidelines for calculating waste generation rates and justifying access arrangements. Essentially, buildings will need to be consciously designed with responsible waste handling in mind, which means providing sufficient space for sorting and storage of various types of waste, including hazardous waste (see Figure 2).
Figure 2: Waste area design should provide sufficient space for sorting and storage of various types of waste, including hazardous waste.
Forward thinking
When buildings are responsibly designed, it will also support pathway 2, on-site recovery, for net-zero waste certifications. The waste area needs to be large enough to accommodate the on-site separation needed to maximise the recovery of recyclables.
Another important consideration is the need for businesses to separate organic waste on site, which also requires adequate space for the separation and handling thereof. For instance, in the Western Cape, there is a ban on sending organic waste to landfills, with a 50% diversion target by 2022 and 100% by 2027.
This regulation is anticipated to be implemented nationally, highlighting the importance of considering the size of waste areas in future designs.
Addressing space constraints
In buildings with space and access constraints, two main waste solutions are commonly used, especially in developed countries.
The first is waste chutes, which are prevalent in densely built areas. They eliminate the need for wheelie bins by directing waste straight to the waste area below. Ideally, buildings have two or three chutes to enable some level of source separation.
The second option is off-site sorting at material recovery facilities, which are used when space is extremely limited. Source separation on site is always the preferred method though, as it improves the recovery rate of recyclables and minimises contamination.
Designing for net-zero waste requires allocating adequate space for effective on-site separation and recovery, ensuring waste management aligns with sustainable practices and future regulations.
Issue: How to achieve a net-zero waste certification.
Solution: Best practice advises on following the net zero pathways, on-site activities for the sorting and handling of waste, including organics, and aligning to the New Build Green Star Tool V2 to ensure adequate space is made for waste from the design phase.

Melissa van Rensburg, Senior Consultant at Green Gap Consulting.
For more information, contact Green Gap Consulting:
Email: info@greengapconsulting.com
Website: www.greengapconsulting.com
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