ZEMCH 2015 - International Conference Proceedings | Page 580

The innovative bio-inspired approach presented - far from the traditional human attitude to dominate and improving it - seeks to solve the architectural problems by learning from the sustainable
parallel solutions in nature. This contemporary philosophy states that is it possible to improve the
quality of the architectural elements through the examination of nature and its systems, structures and shapes, in order to get inspiration for the design of the architectural models.
As the living beings are protected by their skin, which is an intelligent organ able to perform
multiple functions, the buildings are externally defined by the building envelope, which regulates
the relation between the habitants and the external environment. The approach proposed by the
research project aims to promote the architectural design of a new dynamic envelope building
able to interact with the variable climatic context, like the animal skin.
Some animals can change their body colour both to protect themselves from the external environment and to mask their position and movement. Indeed, the octopus is able to use its dark
ink to attack and defence itself, as well as to change colour, texture and shape, to become colour-blind to completely camouflage its location (Bar-Cohen 2011). The chameleon can ra pidly disguise itself by using its cells chromatophores, which contain basic yellow and red pigments, the
layer reflecting blue and white light, and the melanophores containing the black to dark brown
pigment melanin, which darkens its colour (Kalauni, Gupta, Bharti 2014). The side-blotched lizard
is a reptile that lives in the desert, being able to survive to the climate thanks to the thermoregulation of its intelligent skin: the skin pattern is typically dark on the back of the lizard for sunlight
absorption and light on the abdomen for reflecting heat from the ground (Mazzoleni 2010).

Figure 3: Animals able to change their body colour: chameleon (photo by Will Stanley), side-blotched
lizard (photo by Rob Schell), octopus (photo by Shlomit Ouziel)
In order to imitate these natural properties and to implement them in architectural design, the
research project proposes an innovative approach for the building envelope generation process.
Moreover, several cases during the last years opened new perspectives for the development of
potential technical solutions for the building envelope, in order to promote an innovative bio-inspired approach to the architectural design.
Focused on the optimization of the façade component, the project introduces a new layer constituted by a thermochromic paint to be applied on the external side of building’s exterior thermal
insulation composite system (ETICS). This architectural solution for the refurbishment interventions could decisively increase energy efficiency of the envelope, conferring a large and controlled variability during day/night and summer/winter cycles.
In particular, the project suggests the installation of the previously mentioned prefabricated
panels on the façade of the existing buildings, combined with a thermochromic coating applied
directly on the planar external surface of the disposable formwork containing the thermal insulation material. Due to their dynamic optical properties, the thermochromic materials are able to
change their colour thanks to the variability of their physical characteristics depending on the
temperature variation, during the different hours of the day and the different seasons of the year.

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ZEMCH 2015 | International Conference | Bari - Lecce, Italy