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174 STRUCTURE AS ARCHITECTURE▲ 8.11 Recessed lights in stub columns. ▲ 8.12 Stadelhofen Railway Station, Zürich, Switzerland,Santiago Calatrava, 1990. Integration of structure and artificiallighting.MAXIMIZING LIGHTWhere requiring high levels of daylight or transparency through thebuilding skin, architects adopt a number of stances towards structuraldetailing. Maximum daylight implies reducing the silhouette or shadow ofstructural members. The two most common methods are either to minimizestructural member sizes, or to penetrate typically sized members.Transparent structural members are also becoming increasingly popular.Detailing to minimize structural sizeChapter 7 discusses how the dual architectural qualities of complexityand lightness can arise where structural dimensions are minimized.Simple calculations show that if one tension rod is replaced by twosmaller diameter rods with a combined strength equal to the original, thearea of the structural silhouette is reduced by approximately 30 per cent.With four rods this reduction in silhouette reaches 50 per cent – themore members, the more light, but also more visual complexity.At 237 m long, 79 m wide and 28 m high, the vaulted Trade Fair GlassHall, Leipzig, was the largest single-volume glass building of the twentiethcentury. The tubular steel exoskeletal structure consists of ten primarytrusses that stabilize a grid-shell (Figs 8.13 and 8.14). Triangular incross-section, the arched trusses are fabricated from relatively smalldiametersteel tubes whose varied wall thicknesses reflect the intensityof the structural actions. A resolute strategy to achieve maximum transparencyexcluded potentially large-scale members from consideration.As Ian Ritchie, project architect, explains:Transparency was a key design objective. We wanted to minimize thestructural silhouette, and in fact the total area covered by structure in any