Buro Happold's early projects ranged from designing giant fabric umbrellas for Pink Floyd concerts to the Munich Aviary and the Mannheim Multihalle, both with Frei Otto, an architect who repeatedly worked with Buro Happold on projects which pioneered lightweight structures. The Mannheim Multihalle was a timber gridshell of 50 by 50 mm lathes of hemlock of irregular form, depending on the elasticity of spring washers at the joints for its flexible form. It was one of the first major uses of structural gridshells.