clarke's design of stained glass for the great south window of the grandstand at royal ascot racecourse, as part of the £185 million 2004-2006 redevelopment funded by allied irish bank and designed by populous and buro happold, was to have been the world's largest work in the medium. the project received royal approval from queen elizabeth ii, but problems arose during the redevelopment's construction that prevented the installation of the window, as redressing them would have necessitated a delay to reopening the racecourse, leading to the project being scrapped. commissions for two roundel windows in derby cathedral (1976), and for the north transept windows of salisbury cathedral (2014-2019), were not approved by the church of england. clarke worked on designs with norman foster for incorporating stained glass throughout stansted airport, and a glass tower for the willis faber and dumas building; i. m. pei for a public sculpture for the shard at london bridge; zaha hadid on mosaic and stained glass for a building in spittelau, vienna, and kapsarc, saudi arabia; with will alsop on mosaic and stained glass for crossrail paddington, and stained glass for hungerford bridge; and stained glass for stratford international.