For two decades, the program has spotlighted projects that push beyond compliance to demonstrate what truly regenerative, forward-thinking design can achieve. In an era defined by climate urgency, these awards do more than recognise excellence; they set benchmarks, inspire industry-wide change, and elevate the importance of sustainability as a core design imperative rather than an optional add-on.

Within this context, the prestigious Best of the Best category, proudly sponsored by Autex Acoustics, represents the pinnacle of achievement. It celebrates projects that not only meet rigorous sustainability criteria but redefine them, demonstrating innovation, measurable impact, and enduring value for both people and planet.

As architects, designers, and landscape practitioners grapple with increasingly complex environmental and social challenges, this category highlights what is possible when ambition, collaboration, and technical rigour align.

Last year’s winner, TCL’s Breakout Creek / Purruna Pari Stage 3, exemplifies this ethos. Transforming a highly engineered flood channel into a thriving blue–green corridor, the project demonstrates how ecological restoration, infrastructure performance, and community use can coexist—and even reinforce one another.

With a projected climate-positive outcome within just 11 years, the project showcases how data-driven design, long-term stewardship, and deep cultural engagement can create landscapes that not only repair environmental damage but actively contribute to a healthier future.

As the awards celebrate this significant milestone, the call to action is clear: now is the time for designers and practices to step forward and share their most ambitious, impactful work.

Entering the Sustainability Awards is an opportunity not only for recognition but to contribute to a growing body of knowledge that is reshaping the profession.

In its 20th year, the program continues to champion the ideas and projects that will define the next generation of sustainable architecture—so if you’re leading change, this is your moment to be seen.

Architecture & Design: The project is described as achieving a climate-positive impact within 11 years. Can you explain the key design strategies and metrics that enabled this outcome, and how you balanced ecological performance with long-term maintenance and community use?

TCL: The climate‑positive outcome is based on Climate Positive Design’s Pathfinder modelling, which projects that Breakout Creek / Purruna Pari Stage 3 will become climate positive within 11 years.

With a total project area of 223,866 m², around 60% of the site is planted, supporting significant long‑term biogenic gains as the landscape matures. We reinforced that planted system with habitat‑forming landforms and structure, including 111 new trees and 245,000 new plants, and the creation of 7,164 m² of river bench and 1,480 m² of habitat pool to build durable ecological edges and refuge conditions.

The wetland system is central to this performance: 11,400 m² of permanently vegetated wetlands that treat around 60 million litres of stormwater annually and prevent approximately 95 kg of nitrogen reaching Gulf St Vincent each year. These working systems are designed to keep delivering and compounding ecological value over decades.

Balancing ecological performance with long‑term maintenance and community use was fundamental to the design. We made maintenance access a first‑order design requirement so the system could be cared for after high‑flow events and through its establishment period.

Shared‑use paths provide maintenance vehicle access with layout areas every 500 metres, informal trails along the wetlands are vehicle‑rated for debris cleanup, and the low‑level river crossing is trafficable to 6.0 tonnes with removable deck panels to support ongoing maintenance.

Community use was celebrated through legible, safe, accessible infrastructure, including 4.1 km of DDA‑accessible paths plus 2.1 km of informal trails and crossings and by extensive lighting and passive surveillance achieved through path elevation and an off‑street elevated connection through Apex Park. This approach enables high everyday use while protecting sensitive habitat areas and supporting enduring community enjoyment of the site.

Breakout Creek evolved from a highly engineered flood channel into a multifunctional blue–green corridor. What were the biggest challenges in reworking this constrained, infrastructure-heavy site into a system that supports habitat, recreation, and stormwater treatment simultaneously?

It was essential that the current levels of flood conveyance could not be compromised. This is still a levee‑controlled corridor that plays a critical role in flood protection, so the transformation had to occur within tight hydraulic and operational constraints.

Every habitat bench, wetland edge, crossing, and planting zone needed to be carefully coordinated to improve ecological function and public experience without increasing flood risk or creating an unrealistic maintenance burden.

The second major challenge was the site’s physical constraint. It is a long, narrow corridor already dominated by existing infrastructure, and Stage 3 needed to fit constructed wetlands, extensive revegetation, shared paths, informal trails, crossings, viewing platforms and shelters into that space while remaining buildable.

Construction staging in a live waterway environment was complex, requiring careful sequencing around variable flows and wet conditions, with strong construction environmental controls to manage sediment and protect water quality during delivery.

Alongside flood conveyance requirements and construction complexities, a major challenge was balancing equitable and safe public access without fragmenting or degrading habitat.

We addressed this by designing a clear hierarchy of movement and a robust set of edges and refuge areas to allow recreation to coexist with sensitive wetland and riverbank habitats over time.

The project embeds Kaurna cultural interpretation and collaboration throughout the design process. How did working with Kaurna representatives influence both the spatial design and the storytelling elements of the landscape?

Working with Kaurna representatives from the concept stage influenced both the design’s spatial structure and the way story is experienced across the site. Cultural interpretation informed where people arrive, pause, and move through the landscape.

The project integrates existing Eucalypts within the design and includes nine integrated artworks by a Kaurna/Ngarrindjeri/Yankunytjatjara artist, Allan Sumner. These elements are positioned to be encountered through movement along accessible paths, crossings and gathering points so that storytelling is embedded in the day‑to‑day experience of the place.

The project accommodates ecological restoration, flood management, public access, and ongoing uses such as horse agistment. How did the design team negotiate these potentially competing demands?

At the project outset, through community and stakeholder engagement, we developed nine key design principles as a shared decision framework throughout the project.

Those principles made decision-making explicit and consistent: habitat creation and water quality improvement needed to be achieved while maintaining flood conveyance, and public access had to be equitable and safe while protecting sensitive ecologies and allowing ongoing site uses.

In practice, that meant designing for coexistence rather than displacement. The project delivers substantial ecological systems as well as a well-loved community recreation asset. Importantly, the ongoing presence of horses was retained as part of local identity. The site includes 21,060 m² of irrigated agistment and improved horse infrastructure.

This project has been recognised as a benchmark for transforming degraded waterways into healthy ecosystems. What aspects of the Breakout Creek approach are most transferable to other cities, and what conditions are critical for replicating its success?

What is most transferable is the approach of treating legacy flood and stormwater infrastructure as blue–green infrastructure that can deliver multiple benefits at once: measurable water quality improvement, habitat restoration and biodiversity uplift, and high‑quality public access and amenity, while still maintaining flood protection performance.

Another highly transferable aspect is the method of design delivery. Working closely with the clients and stakeholders, our team established a clear set of shared principles early, then used modelling, multidisciplinary coordination and detailed design resolution to deliver within real constraints.

Equally, the project demonstrates that long‑term success depends on designing for stewardship. Practical maintenance access, durable infrastructure, and clear movement hierarchies help ensure the ecological system can be cared for and protected, particularly after high‑flow events.

The critical conditions for replication are aligned governance across landholders, councils and water/flood managers. Definition of clear flood and operational requirements established early, through genuine Country and community involvement from the outset.

Alongside this, sufficient resourcing for the establishment period is essential, as is adaptive management to enable the living system to mature into what it was designed to be.

Entries are now open for the Sustainability Awards 2026. Enter now.

Images: Breakout Creek / Purruna Pari Stage 3 by TCL / Photography by Jackie Gu

Best of the Best: Celebrating two decades of sustainable design excellence

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