Petra Heights, a new apartment development in north London, is held up by an exoskeleton made from more than 1,000 tonnes of volcanic stone.
Architecture studio Groupwork and engineer Webb Yates designed the frame to carry the building's weight and wind loads without a concrete stability core or steel reinforcement bars.
The three-block project contains 22 apartments. Its stone frame is made from Sicilian basalt and Norwegian larvikite, and the building still uses concrete for its basement foundations and floor slabs.
The designers say the structure's materials and construction have a lower carbon footprint than a comparable reinforced-concrete building. The project is a demonstration, not a finished answer, but it gives builders another material to study.
