Posted by admin on Wed, Oct 08, 2025 @ 4:22 PM
The Next Life Project: From Artwork to Community Legacy
Every great story deserves another chapter.
If you work in urban planning, design, or development, you understand both the responsibility and the privilege of shaping how future generations experience their communities.
At Citygreen, the part we play is often invisible, hidden beneath roads, pavements, and plazas worldwide, supporting the growth of greener, cooler, more liveable cities.
Our foundational solution is Stratavault: a 100% recycled soil cell system that enables trees to thrive in hardscape urban environments. Manufactured locally in Australia and North America using regional plastic waste, Stratavault supports circular economy principles from the ground up, literally. And now, one remarkable Stratavault installation is about to prove just how far that circularity can reach.
The cooler, greener, more liveable public places this infrastructure is built to support.
The Construction Economy We Need to Change
Every year, Australia’s construction industry creates millions of tonnes of waste. Materials designed to last for generations are often used once, removed, and discarded.
Yet what if the story didn’t have to end there? Sometimes, a different story emerges, one where materials aren’t discarded, but transformed.
When Infrastructure Becomes Art
In 2024, Citygreen was approached by artist and former engineer Mike Hewson and the Art Gallery of New South Wales. Their vision? A 2,000+ m² interactive exhibition, The Key’s Under the Mat, constructed almost entirely from salvaged materials, housed inside a former WWII oil tank.
They needed a structural system that could:
- Support construction equipment, public foot traffic, and playgrounds
- Enable underground services like power and water to be hidden
- Align with a strict reuse/recycled materials mandate
Stratavault ticked every box. The exhibition opened on 4 October 2025, built on 3,507 recycled Stratavault modules and a soil vault matrix of around 680 m³, enough to support 30–60 trees, depending on the required soil volume, and is currently supporting one of Sydney’s most talked-about gallery experiences.
Installation of Mike Hewson’s ‘The Key’s Under the Mat’, artwork © Mike Hewson. Images © Art Gallery of New South Wales.
The Story Beneath the Story
Mike Hewson’s The Key’s Under the Mat installation has welcomed more than 500,000 visitors. Inside the historic Nelson Packer Tank, reclaimed materials were transformed into an immersive public artwork that challenged the way we think about waste, value and possibility.
But hidden beneath every visitor’s footsteps was another story, a foundation made from 100% recycled Australian plastics, designed to disappear, protect soil, and support trees for
generations. Invisible, yet carrying everything above it.
Most exhibitions finish. They are dismantled, packed away and disposed of. This one doesn’t.
From Art to Earth: Be Part of the Next Chapter
The Key’s Under the Mat is open to the public until 23 August 2026, with an end-of-life goal of ensuring that as much of the exhibition material as possible finds a new purpose and home after the exhibition closes.
In keeping with that spirit, we are calling for Expressions of Interest to determine the next chapter for the exhibition’s Stratavault modules. Visionary designers, developers, and local governments, this is a unique opportunity to:
- Secure the world’s most advanced soil cell system (at below-market pricing)
- Embed true circularity into your next streetscape, park, or public realm
- Connect your project to a nationally recognised piece of cultural placemaking
Imagine this legacy continuing beneath civic squares, main streets, regional parks, nature play spaces, town-centre renewals and community places anywhere people gather, celebrate and belong.
This isn’t just about infrastructure. It’s about legacy: honouring a cultural collaboration by extending its impact into our streets, parks, and cities. Selection won’t be based on project size or purchasing power, but on the lasting difference your community can create.
Product quantities and availability: Late 2026 onward.
Application closes 31st August 2026.