The Stone Demonstrator is a three-storey prototype building shell on show at the Earls Court Development site in London, at Empress Place.
It is an off-site installation from the Design Museum’s Future Observatory research programme.
The 6.5-metre tall structure is a low-carbon construction prototype that puts pre-tensioned stone building techniques to the test. It has been designed by architecture practice Groupwork with engineers Webb Yates and Arup, and built from prefabricated natural stone – now called augmented stone – from The Stonemasonry Company.
The Stone Demonstrator is a prototype of an alternative way to build that reduces carbon emissions by approximately 70% compared to a reinforced concrete frame, it is claimed, and 90% compared to a steel frame.
The Stone Demonstrator consists of stone blocks that are connected by steel tendons and compressed to create pre-tensioned beams and columns. The floorplates are a mix of pre-tensioned stone slabs, combined with timber joists and a roof of dowel-laminated timber (DLT). The structure has a self-supporting facade of stone bricks that are 90% lower in carbon emissions than London’s vernacular of fired clay bricks.
Alongside the Stone Demonstrator prototype, Future Observatory has also funded engineers at University College London to develop a guide to designing stone structures. The design guide, led by Professor Wendel Sebastian at UCL, provides a tool for the construction industry to make stone structures easier to adopt, and is regarded as a step towards a building code for stone.
Future Observatory is the Design Museum’s national research programme for the green transition. The programme is coordinated by the museum in partnership with the UKRI Arts & Humanities Research Council (AHRC). 
The display will be open to visitors from 24th  November 2025 at Earls Court Development site, Empress Space, London SW6 1TT
Got a story? Email news@theconstructionindex.co.uk
