Climate adaptive skins: Towards the new energy-efficient façade

Abstract

Façades perform many different functions and are made up of many different parts and materials. Mike Davies was the first to describe a façade made up of one layer that was still able to cater to different functions. In an effort to realise this 'polyvalent façade' as described by Davies, multiple features have since been integrated into the façade, each addressing a specific need. Building skins that are considered to be at the forefront of modern façade technology however are basically all variations on the same theme, hardly doing anything but reacting to the current environmental conditions and the situation created by the façade itself. As such, they are ad hoc devices, able to adjust to a specific circumstance at that specific time, but unable to save, store or prepare for another circumstance. The outdoor climate changes through time and season, alternately supplying energy to and drawing energy from the building skin. Most modern façades have no means to buffer between the two, other than trapping air in a double skin façade to use as a warm blanket in winter. Although some buildings utilise thermal mass in floors/ceilings and aquifers to store heat/cold between day/night and seasons, these are technologies that function independently from the building skin, aiding the building installations. Climate Adaptive Skins (CAS) should differ from 'conventional' façades in a way that they are able to adjust their characteristics to and mediate between the changing environments. By doing so they are able to provide a comfortable indoor temperature, lighting level and air quality (parameters influencing energy consumption) without excess use of energy.