In the hands of international façade construction specialist seele, steel and glass are turned into seemingly weightless building envelopes. seele designs and builds plate and shell structures in single- or double-curvature structures such as glazed roofs and atria, and curving roofs with amorphous forms. Or gridshells, cable net façades and tubular structures in complex forms with multiple glass infill panels. Fascinating free-form surfaces and maximum transparency are the hallmarks of such façade construction solutions. And it is not only their looks that set standards. seele’s designs also take care of interior climate functions, e.g. with highly complex glazing, integral ventilation flaps, movable louvres to redirect the incoming light or movable photovoltaic panels. On request, seele can also integrate lighting, heating, fire detection systems, drainage installations and moving elements plus their drive mechanisms.
Even the draft design phase can be called high-tech; steel glass designs are put together first as detailed, complex 3D models. The high level of engineering proficiency at seele serves to reduce the design radically to the minimum number of visible loadbearing members. Early stages of the design work involve combining forms, structural systems and materials to solve the client’s structural, architectural and aesthetic requirements in the best possible way. Parameterised data can be used to simulate scenarios and hence plan long spans without intervening columns.
Every seele steel-and-glass design is as unique as its underlying concept. Pioneering solutions are usually the outcome, e.g. the Cutty Sark conservation project. In that project the company optimised the design and appearance of the toggle system so that the glass fixings could be concealed in the joints in the cavity between the panes using the “sefix” system. Other examples of solutions created by seele are pretensioned screw connections concealed in framing members and screw connections that, compared with welding, permit a high degree of prefabrication plus safe and fast erection.
Bending glass is one of the company’s pre-eminent skills. One cold bending technique involves forcing the glass into a curved shape over a rigid framework and then fixing it in this position with clamping bars. This increases the load-carrying capacity, and distributed loads such as wind and snow are primarily carried via membrane forces, less via bending. Consequently, the thickness of the panes can be reduced – and the budget, too. When that method reaches its limits, seele switches to hot bending and cold bending by lamination. Hot bending involves bending the heated glass to the desired form and then cooling it so that it retains the curved shape. In cold bending by lamination, the laminating film placed between two panes of glass holds the glass in the desired curved form.