Through windows allow you to see inside and out, light, air and heat are not always entirely welcome. In such cases, protective elements that regulate the light, deliberately deflect light or provide complete shading are recommended. They also regulate visual references, as well as the permeability for air and heat. As part of the window system, depending on how they are arranged, how they can be controlled and whether and how they are repeated, shading elements can influence the design of the façade of a building if used on a large scale. A changeable appearance of the façade can be created by using moveable elements that can be aligned either manually or mechanically depending on where the sun is and the individual wishes of the user. Fixed shading elements or "filters" can also be used to provide security.
The original function of the window shutter was to protect the inside against the wind and weather. When it became possible to glaze windows, the task of the window shutter was also to protect the window glass. The window shutter continues to function as sun protection, privacy protection, heat protection at night, sound protection and, as it can be locked, as burglary protection. Initially created as a closed boarded shutter, over the course of time smaller translucent or transparent openings were added. Later, closed areas became diagonally set slats that, as they were further developed, became moveable and could be adjusted manually. Today, window shutters are increasingly made from aluminium but overall are being generally replaced by roller shutters. However, current architecture still contains successful examples of a modern interpretation of this classic window element, designed for example as a sliding shutter or folding revolving shutter.
Lamellar structures offer a flexible system: The slats can be operated and aligned depending on where the sun is, while at the same time allowing a clear view provided the slats are not set completely flush with the outside wall. The perfect solution is uncoupled systems in which the individual slats can be controlled separately. Semi-transparent slats can allow more light into the room and give an even better visual perspective.