Page 140 - ELEMENTS EUROPA (EN)

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STEEL AND GLASS

ANTI-EXPLOSION FACADES THE LANTERN’S GLAZED FACADE

The Europa building is a glass fortress. Protection does not During construction, a mechanical fixation was added to the
come from a massive facade but from a succession of glazed windows constituting the lantern’s facade, complying with the
layers each of which offers adapted resistance according to the NBN B25-002 1 standard, even though the latter was published
aggressions it may undergo, considering the resistance others after the study’s completion. This decision results from the
offer. The atrium facade internal layer endorses the pressure need to make the new Council head office in compliance
caused by an explosive blow in particular, by inflation as a sail with the most advanced security standards at the time of its
would. When exposed to such stress, keeping laminated glass commissioning. Small circular mirror polish stainless steel plates
panels into place can only be guaranteed if the fixation glazing are placed in all the joins between windows in the middle of
stops are wide and rigid enough. Classical curtain walling is out each element’s sides.
of the question for such an application.
In this instance too, technical considerations result in the
A specific fixation system was developed, made up of architectural enrichment of the lantern by adding a new
70 x 6 mm stainless steel bead blasted plates, screwed to the perceptual size in it.
very sections of the structure by means of welded threaded
rods ending with mirror polished stainless steelcap nuts. Glazing The Postsparkasse
panes are tightly pinched between the structure and glazing (arch. Otto Wagner)
stops thanks to little compressible synthetic rubber straps. in Vienna.

The same system applies to the internal and external facades
of the accreditation zone surrounding the atrium on the
ground floor. This ensemble being particularly exposed, the
plate thickness has been reinforced from 6 to 8 mm. Control
and security posts outside the building too are equipped with
identical facades.

Even though conceived with security concerns in mind, those
elements make the architectural expression of the ensemble
richer by adding size into the perception of architecture.
Indeed, with its 2.70 x 1.77 m mesh, the facade grating is in
metric scale whereas rows of cap nuts bring in a centimetric
one. The latter are placed apart from one another at variable
distances according to how intense the pressures are but the
gap is always a submultiple of the facade grating’s module. Their
mirror polished finish (achieved through a chemical process)
contrasts with the shaded mat texture of stainless steel bead
blasted plates.

This architectural shaping is based on architect Dom Hans van
der Laan’s principles, who rediscovered the seven perceptible
sizes in architecture in 1960 (Plastic number, fifteen lectures
on architectonic organisation, Leiden, E.J. Brill publisher). It is
similar to Otto Wagner incorporating aluminium rivets to the
marble facade of the Postsparkasse, built in 1906 in Vienna.