Seeing Through Glass: A Technical Review
The skin, independent of the building shell, is made up of three main groups of elements: the opaque elements, the transparent elements and the translucent elements (European Commission 1999). This traditional view of the characteristics of envelope materials is now questionable in the context of the speed of technical innovation in building materials, and in particular in glass. A glass pane, for example, can now be transformed into either a translucent or an opaque state by the manipulation of electric currents. New technology allows extensive use of glass as internal separators as much as in façades. This development is expected to receive a wider acceptance in public buildings where, in the light of the threat from terrorism, there is an increasing demand for surveillance, clear surfaces and visual inspection. The transparent components of the building envelope are usually the most interesting parts, due to their dynamic nature. They are more responsive to short-and long-term changes in interior and exterior conditions. They have more complex functions, allowing views and communication with the outside, providing heating through the controlled use of solar gains, and cooling by shading and ventilation. External shading, daylight enhancing devices and solar control blinds can play a signifi cant role in fi ltering heat and light through a building’s skin, particularly when used in combination with glazing selection and ventilated façade strategies that integrate natural processes.