STRUCTURAL GLASS FACADES - USC School of Architecture

The application of trusses as part of a glass façade
system brings other considerations; the glazing plane
and grid will dictate certain geometric parameters of the
truss system, deflection criteria must be considered,
limitations in the design of boundary supports may
eliminate certain system types, the intended glass
system must be evaluated in terms of the supporting
structural system (these issues are discussed further in
Chapter 7). However, aesthetic considerations are
always in play, and are often the primary design driver.
Long-span façades make use of exposed structural
systems. The emphasis has been on elegant structural
Figure 2.6 Spertus Institute, Chicago;
faceted glass façade, Krueck Sexton
Architects, 2007 (Built Chicago 2008).
system designs, highly crafted system components,
and a general dematerialization of the structure in an
effort to enhance overall system transparency.
Figure 2.7 shows a simple truss system with tension
rod bracing and a horizontal purlin mirroring the exterior
glazing grid can provide relatively high transparency
with considerable economy over more complex truss
systems. Virtually any glass system can be adapted to
this truss system.
Geometric configurations of simple truss types include
Figure 2.7 Simple truss system with
internal tension rod bracing and
rectangular exterior chord (ASIDI).
variations of Pratt, Warren, and Lenticular trusses. Various truss types are represented in
Figure 2.8. Truss design is a function of the structural considerations of span, loading, pitch,
spacing and materials. A deflection criterion for truss systems making predominant use of
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