How this Sydney CBD tower achieved a 6-star NABERS waste rating

In Sydney’s CBD, a 51-level premium commercial tower has quietly achieved something extraordinary: a 6-star NABERS waste rating — the highest possible rating under the national benchmarking system.

Only a small number of buildings nationally have reached 6 stars. Two of only three known 6-star NABERS waste-rated buildings in Sydney’s CBD are maintained by SKG Services, a 100% Australian-owned family business that has delivered cleaning, maintenance and security services for 50 years.

But the result was not achieved through surface-level sustainability initiatives or upgraded bin systems. It was the outcome of a comprehensive, whole-of-building waste management overhaul designed to deliver measurable ESG performance.

A familiar commercial building problem

Like many large commercial towers, the building was heavily reliant on general waste streams. Waste data lacked visibility across tenants and floors. Contamination risks were high. Reporting was fragmented.

While sustainability ambitions existed, there was limited ability to measure performance accurately or demonstrate genuine ESG progress.

Without reliable data and coordinated systems, waste management remained reactive. Improvement was difficult to quantify, and landfill diversion remained lower than desired.

Rethinking waste as infrastructure

The facilities services team approached the challenge not as a cleaning issue, but as an operational opportunity. The objective was clear: redesign the entire waste ecosystem to move from fragmented disposal to coordinated diversion.

The transformation began with a fundamental redesign of the building’s waste streams.

Redesigning the waste system

A mixed recycling model was introduced to capture materials that had previously been sent to general waste. Bin ratios were reversed to favour recycling over landfill and organics were separated.

Most importantly, waste collection was centralised to a single onsite processing area equipped with a weigh station — every waste stream is now weighed or recorded before leaving the building. This shift from estimated volumes to verified measurement changed everything.

Data-driven accountability

Measurement alone is not enough without visibility.

A QR-enabled tracking system was introduced to log waste by building, floor and tenant. This level of detail allows building management to identify patterns, contamination risks and improvement opportunities in real time.

Unlike traditional quarterly or periodic waste audits, contamination monitoring now occurs daily, meaning issues can be addressed in real time rather than months later. Monthly reporting provides building owners and asset managers with clear ESG data, including:

• waste volumes by stream
• diversion rates
• contamination levels
• identified risks
• improvement opportunities.
   

This data-driven approach has shifted waste management from an operational task to a measurable performance metric.

Behaviour change through engagement

Infrastructure alone does not deliver transformation. Tenant engagement proved equally critical, driven through pop-up activations and ‘trash-talking’ sessions which took place with all tenant representatives. Rather than enforcing change through policy alone, the program focused on communication and participation.

Standardised, co-branded signage was rolled out across common areas and tenancies to eliminate confusion caused by inconsistent labelling systems. Clear messaging and visual consistency significantly reduced contamination. The engagement strategy created a sense of shared accountability between building management and tenants.

Expanding the waste ecosystem

The project extended beyond basic recycling.

A single operator now manages the collection and management of all waste streams across the building, including:

• organics
• reduced general waste
• secure paper destruction
• onsite baled paper and cardboard recycling
• coffee cups, batteries and e-waste
• light tubes and toner cartridges
• construction waste partnerships.
   

Recovered materials are either recycled, composted or converted into Processed Engineered Fuel (PEF), helping reduce reliance on fossil fuels.

The approach prioritises circular outcomes wherever possible, ensuring materials are diverted from landfill and re-enter productive use streams.

The results: from 2.5 to 6 stars

Within the first year of implementation, the building’s NABERS Waste rating increased from 2.5 stars to 5 stars.

By the second year, it had achieved 6 stars — the highest rating possible. The uplift was structural and reflected redesigned systems, consistent measurement, tenant engagement and continuous monitoring. Most importantly, the building now has defensible ESG reporting supported by verified data.

Lessons for commercial buildings

This case highlights several key lessons for other commercial towers facing similar challenges:

• Waste needs governance — measurement, accountability and reporting are critical to achieving real outcomes.
• Centralised processing and data collection are game changers — without tracking, diversion claims lack credibility.
• Behaviour change requires education and consistency — signage, communication and tenant engagement drive measurable results.
• Daily monitoring prevents regression — contamination management must be continuous, not periodic.
• Circular thinking unlocks additional value — waste streams can become inputs for other industries, reducing environmental impact.
   

With new NABERS waste rules now in effect and ESG expectations increasing, commercial buildings can no longer rely on optics or high-level sustainability statements. Investors, tenants and regulators increasingly expect data-backed performance.

*Tracey Broers is Group General Manager Risk at SKG Services, a national commercial cleaning, maintenance and security services company with a 50-year history.

Top image credit: iStock.com/CreativaImages