Sharing Kolman Boye’s respect and enthusiasm for traditional Japanese joinery techniques, Benchmark used square peg joints, cutting hundreds of square holes, not easy, but a strong component of Japanese joinery. 'In total we made 3,084 separate pieces connected by 1,008 joints to make up the ‘skeleton’ of the Rotunda together with 528 trays for the surface layer, all assembled without the use of nails, screws or glue.  It is a wonderful piece of cabinet making and a tribute to the skills of our craftsmen who have used their fine techniques on such a grand scale,' explains Sean Sutcliffe, co-founder of Benchmark.

At over 3.7m in diameter and the same in height, this was not really a piece of furniture but a substantial yet lightweight structure. With this in mind, AHEC turned to engineers Arup, central to a number of previous AHEC projects, including the 'Timber Wave and 'Endless Stair', to carry out a structural appraisal and prototype tests, in order to inform the construction.