DAM IMPRESSIVE

the aim is a dynamic exchange between
building and environment.
ALPINE is testing what is currently the most advanced
product in facade shade technology for the construction
of Petrom City in Bucharest. A type of venetian
blind is positioned between two panes of glass. This
structure is impressively thin and easy to maintain, and
it helps steer light into the building and optimise energy
consumption.
thin Yet StRong
The development of high-performance membranes and
foils has been a real leap forward in terms of finding the
right material for building facades. These filigree materials
inspire architects to bold designs, but they also
bring with them a series of outstanding properties. For
instance: ETFE film (a copolymer made of ethylene and
tetrafluoroethylene) is enormously durable (it lasts for
more than 20 years), extremely robust, maintenancefree,
non-combustible, self-cleaning, recyclable and
95% transparent.
ALPINE used this innovative material some years back
when it created the largest ETFE membrane shell in
the world for the facade of the Allianz Arena in Munich
(66,500 sq m, more than eight times bigger than the
pitch inside). A total of 2,786 diamond-shaped cushions
made out of the 0.2-mm-thick film cover the roof
and facade of this football stadium. The cushions were
made in identical pairs, but no two pairs are identical,
which means that around 1,500 different diamonds
were required. For the project team, fitting them in
place was, at times, quite tricky. ‘Getting the right materials
to the right place at the right time was a logistical
challenge: the cushions, their sealing adaptors, and the
profiles used to clamp them in place,’ recalls Kay Gerber,
project director. ‘We had to number the cushions.’ Each
cushion is now permanently supplied with compressed
air. The pressure is monitored constantly and continually
adjusted (e.g. summer/winter). The translucency
of the ETFE film allows the grass on the pitch to grow
nicely.
The shell of the Allianz Arena can light up in three different
colours. For this special lighting concept, the
film required additional treatment: little white dots
were printed all over it so that the light wouldn’t simply
shine through, and the fluorescent lamps behind
the cushions were given coloured filters. Depending on
which team is playing, the Allianz Arena can light up in
red (Bayern Munich), blue (1860 Munich) or white (e.g.
an international fixture), giving it its spectacular appearance.
fabRiC faCadeS
At the Institute for Lightweight Structures and Conceptual
Design (ILEK, or Institut für Leichtbau Entwerfen
und Konstruieren) in Stuttgart, similarly intensive
research goes on in search of the ideal material for
building shells. There they focus on textiles, and their
interest is in multilayer fabric building shells which
combine the benefits of membrane construction – such
as diversity of form, transparency and low weight –
with outstanding properties of heat and noise permeability.
So-called ‘phase-change’ materials can change
their state to adapt to different temperatures, thereby
absorbing or emitting heat as required. This makes the
building shells developed at ILEK highly adaptive and
pioneering. Once again, nature has been the inspiration.
‘The biological potential for complex interface properties
in covers is very broad,’ states Susanne Gosztonyi, project
manager and member of the Sustainable Building
Technologies Faculty at the Austrian Institute of Technology
(AIT). She is currently involved in this field as
part of the BioSkin project, which is funded as part of
the ‘Building of the Tomorrow Plus’ scheme. This project
researches the potential of biologically inspired energy-efficient
facade technologies. She believes that the
facade of the future ‘will be able to fulfil a wide range of
varying, sometimes contradictory, requirements, and will
do so intelligently, with maximum energy-efficiency and
with a high level of convenience. It will also use a minimum
of power and resources.’ The aim of the study is to utilise
discoveries from biology to create innovative approaches
to new types of facade. ‘The greatest challenge we face
lies in our objective of abstracting phenomena from nature
and translating them into technical functions.’ No less
than 240 potential analogies have already been found in
biology to match 40 required functional profiles. Of the
former, 35 ‘high potentials’ have been selected and examined,
and the principles upon which they work have
been determined. These selected role models will serve
as a source of ideas in the development of futuristic facade
concepts and provide valuable input for the R&D
activities of the building industry. Thus a vision of the
future gradually becomes reality, and the simple wall
becomes a second skin. //
Ü www.bionicfacades.net
Ü www.hausderzukunft.at
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A 100-m aerial
working platform
and nets
stretched out
at great height
were required to
fit the cushions
onto the roof and
facade of the
Allianz Arena.