Unstabilised Rammed Earth in the Garden of the Future
20.05.2025
Garden of the Future, designed by Matthew Butler and Josh Parker and supported by the Gates Foundation, is a gold medal-winning show garden at the 2025 RHS Chelsea Flower Show. It imagines a near-future UK shaped by extreme weather, rising temperatures, and shifting agricultural needs.
Developed in collaboration with Elliott Wood’s Associate Director Sarah Pellereau, Gates Foundation-funded innovators and researchers from the University of Nottingham, the garden design champions climate-resilient crops, circular water systems, and global agricultural innovation that are helping communities adapt and thrive in the face of climate change.
A garden in a near-future UK shaped by extreme weather, rising temperatures and shifting agricultural needs.
Material Response to the Future
At the heart of the garden stands a rammed earth building. A nostalgic nod to traditional materials and a response to climate change, the building's construction is low-carbon, accessible, and regenerative.
Sarah designed the cement-free, unstabilised rammed earth structure, a sustainable opportunity and a technical challenge.
In contrast to cement-stabilised mixes, unstabilised rammed earth relies entirely on precise grading, moisture control, and expert compaction. It is fully recyclable and low in embodied carbon, but technically demanding. Unlike a material you can buy off the shelf, each soil mix is unique and must be thoroughly tested, assessed and refined.
To safeguard the building from water, Gen 0 concrete was used in the capping to lift the rammed earth walls off the ground. The walls were formed entirely from compacted earth, with a 75mm sacrificial wear layer included to account for erosion over time. A generous roof overhang further shields the rammed earth from direct rainfall.
The structure was founded on well compacted hardcore and treated with a transparent, breathable surface protector to limit dusting and water ingress.
Unstabilised Rammed Earth in the Garden of the Future
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“The most powerful thing we can do as engineers is to make our knowledge accessible. The Garden of the Future shows that sustainable materials don’t need to be specialist-only — they can be shared, learned, and scaled.”
Knowledge Sharing in Practice
The Garden of the Future is also a tribute to the global community of problem-solvers, engineers, scientists and farmers who are actively adapting to the challenges of a warming world. The garden draws particular inspiration from countries in the Global South, where creative, resource-efficient solutions are already being implemented at scale.
In keeping with this theme, the rammed earth structure became a platform for knowledge exchange. Sarah worked closely with landscape contractors Acacia Gardens, sharing her expertise, refining the mix to achieve the right composition and providing hands-on support during the construction.
“The most powerful thing we can do as engineers is make our knowledge accessible,” says Sarah. "The Garden of the Future shows that sustainable materials don’t need to be specialist-only — they can be shared, learned, and scaled.”
Circular by nature, at the close of the show, the rammed earth structure can be re-wet, remixed and reused in another structure, or simply returned to the earth.
Building on a Chelsea Tradition
2021 Pocket Park - Gold Medal
The Gold Medal-winning garden by Harris Bugg Studio for client M&G featured an urban pocket park, highlighting the transformative power of small green spaces in improving urban life.
The garden featured over 100 metres of metal sculpture that weaved its way through the space. With different finishes in different parts of the garden, including bronze-copper, matte and gloss, the metal complemented the planting as well as giving a nod to the city's industrial past.
2019 The Resilience Garden - Gold Medal and Best Construction Award
Designed by Sarah Eberle and built by Crocus, the garden was commissioned to celebrate the Forestry Commission’s centenary. It looked to the challenges facing forests of the future and explored how our woodlands can be made resilient to a changing climate and the increasing threats of pests and diseases.
2017 The M&G Garden - Best in Show
Collaborating with James Basson of Scape Design and Peter Harkett of Crocus, we helped realise the dramatic design that took inspiration from an abandoned Maltese quarry.
Featuring massive limestone blocks and drought-resistant Mediterranean flora, the garden delivered a powerful message about the urgent need for environmental preservation through sustainable practices like water conservation, recycling, and composting.
