Urban Nebula was Zaha Hadid’s contribution to ‘Size and Matter’, a project commissioned by the London Design Festival to explore the relationship between a material, a method of manufacture and a design. The material was precast concrete and the method of manufacture, a combination of repetitive precast moulding and computer-controlled variations of the mouldings, to create a family of individual elements with standardised characteristics.

Hadid’s idea was to make a bench with a structure that behaves like a dry stone wall, but lacks the friction, shape and interlocking components that make them stand up – and it also had to be demountable. So, AKT’s first task was to design a connection that would invisibly connect the concrete blocks by replicating the structural features of a dry stone wall. Each block has a stainless steel socket cast into it, and this bolts to an aluminium bracket with two faces to connect to another block. The bracket has sufficient tolerance to take up the variations in the angles of connection.

AKT also analysed the terraced structure around the Royal Festival Hall on London’s South Bank to ensure that the forty-year-old concrete was strong enough to take the considerable extra load of the Urban Nebula.