major works include the 9700 sq ft stained glass apex and windows for the foster and partners-designed pyramid of peace and accord in kazakhstan, the five-story stained glass wall in the lobby of the al faisaliyah center in riyadh for the king faisal foundation, and stansted airport; 21,528 sq ft of stained glass for the royal mosque at king khalid international airport); the mosaic and stained glass ceiling of pfizer world headquarters in new york, for which clarke developed new techniques for the inclusion of two colours in a single sheet of opaque glass (in 1997), and a new stained glass facade (in 2001); stained glass, mosaic, ceramics, and turf-cut chalk drawing for beaverbrook coach house and spa; the stamford cone in connecticut; windows for linköping cathedral in sweden; the papal chapel of the apostolic nunciature to great britain; the world's largest stage sets (for paul mccartney's 1993 world tour) and both the largest stained glass work in great britain and europe, and the largest in the world.