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

2.1 Maintenance
Advanced Building Skins
A panelized façade is generally easier to maintain than a façade assembled in place from individual
components, because maintenance can – much like the assembly process in the first place – engage on
a level of self-contained façade elements.
In the wave wall, the elements do not overlap at all. Thus, every element can be released and lowered
individually, should it be necessary. The only exception are the lowermost elements, which stand on
the ground. Here, the element above has to be taken away first.
3 Timber for the Shape-defining Layer
Critical advantage of the prefabrication system over the original approach is the replacement of the
bent steel tubes by curved timber beams. When bending timber lamellas to produce curved gluelaminated
beams, the springback leads to similar tolerance issues as when bending steel. But contrary
to steel, pre-curved timber beams can then be machined in a CNC mill at high speed and a precision of
some tenth of a millimeter, yielding very exact and completely strainless building components. On top
of that, the shapes are not limited to (series of) arc segments but allow continuous changes in curvature.
Figure 5: CNC-milling a curved glue-laminated timber beam (designtoproduction)
3.1 Embedding Complexity in the Building Parts
But CNC-milling of timber not only allows for precisely curved building parts. It also allows for the
parts to carry much more information about their placement and interconnection. In the Wave Wall
production process, this was taken to extremes by not only cutting the secondary beams with the
correct angle of bank at any point to guarantee a flush connection, but also by notching seat cuts for
each and every cladding board into the beams (see fig. 6). With further seat cuts aiding the assembly
of the substructure frame, the precise position of every part could be identified without measuring
during element assembly – which would have been very difficult due to the curved geometry of the
parts.
Through this concept, most of the geometric complexity of the façade is taken away from the
assembly process and embedded into the individual components. This not only reduces the assembly
effort drastically, but also minimizes (or nearly eliminates) the risk of incorrectly or imprecisely
assembled elements. The oak cladding of the Kilden façade can act as proof of concept: The pin stripe
pattern is nicely continuing across elements without disturbance (see fig. 4).
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