The goal of net-zero waste in building operations is to eliminate operational waste and to ensure that all waste is repurposed or recycled.

Words Kim Hoepfl

is an attractive number

According to futurefitbusiness, waste refers to all materials generated as by-products of production and other operational activities, and which require treatment, repurposing or disposal. This includes both hazardous and non-hazardous manufacturing materials.

There are good reasons to pursue zero waste: landfill side-effects and finite resources of materials whose extraction methods are destructive to human and ecological wellbeing. All segue into the prevention of global warming and having the energy, clean water, fresh air and fertile soil to make life possible for a projected world population of 9.7-billion people by 2050. They are what underpin the purpose of the United Nationals Sustainable Development Goals (SDGs).

Demand for virgin materials can be directly mitigated, reducing the need for landfills, if materials are not discarded. This is a practical task. In answer to the “how” question, GBCSA has devised the Net Zero Waste Certification (Certification 18), which can be applied to both new, existing and operational buildings. Level Two, the operational phase, applies to buildings that annually reduce, reuse, recover and repurpose their waste streams, with the eventual outcome of zero solid waste reaching landfills. Additionally, building management can take waste from other sites and incorporate it into their waste stream treatment. This is Net Positive.

The model of circular economy, by contrast, seeks to stop waste from being produced in the first place.

Let’s look at why landfills are problematic. Landfills exist for the disposal of organic and inorganic materials no longer considered useful, and that therefore count as waste. Landfills sequester the waste that makes it into our natural environment, keeping communities clean. However, while they are necessary, they are not environmentally benign. Here’s why.


Methane, carbon dioxide, nitrous oxide and ozone are gases present in the earth’s atmospheric sheath. They absorb the sun’s heat, but their increasing concentration prevents its escape just like a greenhouse, hence their name, and bring about global warming.

The most pressing landfill concern is the generation of methane gas, which is 84 times more effective at absorbing solar heat than carbon dioxide. South Africa, as a signatory to the Paris Agreement, is committed to transitioning to an economy that will prevent a further global temperature rise beyond 1.5˚C within the next seven years.


Landfills cover multiple acres and usurp the commensurate amount of natural habitat. The land could be put to more constructive purposes such as housing, agriculture or necessary green space, which has psychological benefits for human wellbeing while also reabsorbing atmospheric carbon.


Operational materials such as e-waste, batteries, glass, aluminium as well as some varnishes and paints contain elements of uranium, mercury, lead and radon gas. When dumped their decomposition produces leachate, a toxic liquid pollutant.


Plastic still has a long way to go until it becomes fully biodegradable. Its manufacturing ingredients are derived from fossil fuels, whose processing is greenhouse gas (GHG) emissions intensive. Furthermore, plastic that ends up in our aquatic systems and which is ingested by fish and seabirds results in their harm or death.

Liberty Two Degrees’ net-zero roadmap.


Raw material supplies are finite and need to be conserved.

Keeping materials out of landfills is an obvious solution and requires a redefinition of is considered “waste”. Our current economy extracts virgin materials, makes products with them and eventually throws them away as waste. This is a linear process. The model of circular economy, by contrast, seeks to stop waste from being produced in the first place (Ellen McArthur Foundation). Instead of discarding products, their materials are kept in use as components for something else. This turns waste into something valuable, as Bertie Lourens of WastePlan points out, “Waste is no longer waste. It is an asset that is seeing consistent increase in its value”.

A circular economy is what underpins the transition to renewable materials and energy. It has both organic (biodegradable) and technical cycles (recycling). Brian Unsted of Liberty Two Degrees cites these as being the greatest impact areas for the treatment of operational waste. In its organic cycle, organic materials such as food are composted or anaerobically digested. During its technical cycle, products are shared, leased, re-used, refurbished or recycled.

To date, there are two buildings that have manged to achieve Net Zero Operational Waste (Virgin Active Constantia and Wild Coast Sun) and one that has managed to achieve Net Positive Waste (House Baldwin Ragaven), which shows that while it’s a complex task, it is possible.



Identify and quantify waste streams
A company’s first step should be an analysis of the types of waste generated. A thorough waste audit – which produces high quality data – will do this for you, by examining what you are disposing of and opportunities for its diversion from landfill. Unsted continues, “We went through a robust process to understand waste management practices that would align with our goals. To ensure cooperation, we needed a model that would reward service for recycling and grant tenants’ rebates for supporting recycling initiatives.”

The GBCSA methodology undertakes actual measurements of operational waste streams, including audits and waste management plans. Pathways 1 & 2 demonstrate waste management practices are in place through ongoing waste measurement and data collection. Here is an example: Waste is collected at source, meticulously sorted and weighed, which is imperative to avoid contamination. Contamination occurs when packaging is marred by traces of food, raw meat, blood or oil, for example, and cannot be recycled. The resulting data is recorded in a report of your waste profile which details all your categories of waste (food, glass, plastic, paper, batteries, etc), their quantities, and indicates how much is recyclable, or is biodegradable. Accurate data reporting is therefore crucial to enable a full view of your business’ environmental impact.


Draw up a waste management plan
A waste management plan determines how waste streams can be appropriately treated and by whom – on site or third parties – targets to be reached and should be in accordance with GBCSA’s Green Star Existing Building Performance tool’s pathways 1 & 2.

That recyclable packaging waste is a valuable manufacturing resource, says Lourens, is because “it is driven by legislation and extended producer responsibility (EPR)”, which states that “packaged items must contain a percentage of recycled content, obligating brand owners eg Shoprite, and packaging manufacturers to incorporate recycled material, thereby elevating its value”.

To ensure that a waste management plan service provider helps you extract this value from your waste, Lourens suggests three points to consider:

Model 1. Waste companies invested in transport equipment and landfill sites profit from waste reaching landfill, which is counterproductive to achieving zero waste.

Model 2. Places staff on site to sort mixed waste prior to recycling, which is also contrary to achieving zero waste. This is because it is method conducive to contamination. The solution is to separate waste at source, which is its direct point of origin eg a kitchen, to prevent it from being mixed with contaminated waste.

Model 3. Service providers who profit from every kilogram diverted from landfill will ensure uncontaminated separation at source.


Recycling solutions
Recycling solutions determine what then happens to that waste and are boosted by innovative technology. The L2D journey to zero waste in shopping malls, the amount of food waste generated by restaurants and fast-food outlets, including fat trap waste, made composting facilities strategically essential to diversion from landfill. In-vessel onsite composting machines enable this, with current diversion rates approaching 90% by Q4 2022. Lourens also cites biodigesters that take in decomposing methane-emitting organic waste, which capture the methane to power gas electricity generators.

Furthermore, technologies like a pyrolytic energy plant (locally available in 2023) close the loop by keeping residual items that cannot be recycled, such as multi-layered plastic laminates like a chip packet, out of landfills. Pyrolysis incinerates items anaerobically, turning solids to gas. A portion of this gas is cyclically extracted from the system and returned to it as fuel. The remainder of the syngas is put through a generator to produce electricity.


Audit performance
The final step of your plan is to regularly audit your performance. An accurate report relies on accurate data collection. Excellent data enables meaningful comparisons and benchmarking to be conducted within portfolios and between contractors. Audit reports provide insight into operational efficiency, and by accurately measuring current performance inform strategic planning targets, to ultimately achieve greater resource recovery. And this is the road to net zero waste.