advanced building skins 14 | 15 June 2012 - lamp.tugraz.at - Graz ...

Advanced Building Skins
2.1 Rationalization of Complex Forms for Fabrication
The successful development of geometrically complex structures is an iterative process of analysis,
modelling, calculation and modification. For conventional geometrically well determined designs like
simple ruled surfaces, one may rely on many years of experience in structural design, the handling of
building materials and methods for manufacturing.
The design geometry can be named to Ceccato [2] as follows: While “pre-rationalised
geometries“ are based on the outset of principles of feasibility, for "post-rationalised geometries“ has
at first to be developed a constructively logical approach which represents the original design in the
best way possible and maintains at the same time the architectural intention.
Actually the basic layers of a building did not change within the last decades. We still have to deal
with common space forming elements like supporting structure, walls, envelopes, and therefore
cladding, joints, profiles and gaskets to ensure a structurally excellent building envelope. The
approach of a construction firm didn’t change so far, but we have to deal now with differing
geometrical parameters and building forms. Del Campo and Manninger [3] stated that additive systems
formed the prevailing method of in the discipline of architecture when it comes to solve problems of
transitions between interior and exterior, while another convention in architectural design is the
usage of detail in the moments of transition between varying material conditions. Constructive details
are the minor part of the whole architectural conception. They are pushed back for the benefit of an
almost fluid surface as an embodiment of a solid freeform shaped sculpture (Figure 6).
Figure 6: Shanghai Pavillion by SPAN Architects and Zeytinoglu
The geometrical properties of a double curved building envelope lead to a large number of elements
and these will influence the following detailing process and, last but not least, will drive the costs. The
goal of developing a rational steel structure which considers the immanent physical properties of the
construction materials is an essential item within the building process. This includes tendering,
aesthetics, structural calculations, detail design, manufacturing and installation on site in consideration
of costs and economy.
Beside the feasibility one of the most influencing parameters are the costs. To maintain the given
budget, quite often optimizations and changes of the original design are necessary, which is called
value engineering. As part of the tendering process each component of the building is evaluated and
assessed from a commercial point of view. The replacement of costly parts by reasonable alternatives
is called value engineering. It is much more cost efficient to use proven standards instead of
prototypes. A close partnership between the contractor and the manufacturer in the course of the
years results in a vast knowledge and expertise in dealing with this process. Waagner-Biro’s focus is
to provide an economic and cost-effective solution which respects the design intent of the architect.
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