"The windows are the eyes of a house" — you look through them to the outside and they also allow you to look from the outside into the inside of the building. They define the intensity of the connection with the outside world, which can be designed to be more open or more closed, depending on the requirements and the desired form of expression. Thus a relationship is created between the public and the private — via the openings a building reveals its inner core, hides it behind a closed façade, or via filters, allows a view to the outside without enabling people outside to look in.
The position in the wall, the size of the window opening and the geometric design of the reveal are features that influence both the design and the desired use of the window. Specifically, these factors influence the view and the type and intensity of the outside perspective, the quality of the illumination and energy factors such as the heat loss via the area of glass but also the use of solar energy.
Arrangement in the wall area
The basis for planning the openings should always be the use of the room behind them. In residential construction in particular, the arrangement of any potential furniture in the room can also play a part in the planning. On the other hand, the placement of openings in the corner of the room, for example, can change the size and shaping of the structure as well as the spatial impression of the room.
Extreme formats such as strip or panorama windows or particularly small openings, as well as a placement that references a special feature on the outside, allow you to work with specific visual references.
To allow a sufficient visual connection in living spaces, the upper edge of the area of glass should be at least 2,20 m and the lower edge at 0,95 m. The width of the area of glass should be equivalent to at least 55% of the width of the room.
Natural illumination is a decisive feature for the living quality and comfort of a room and has a direct influence on human sensitivity and well-being. As a rule, building regulations specify one eighth of the room area (useful area) as the minimum dimension for the opening in living spaces, with the relationship to the depth of the room also playing a role. If the upper edge of the opening is placed higher up, the light is improved significantly — above all in the room depth — and therefore also the daylight factor. In contrast, openings below 0,85 m only have a slight influence on the light incidence. Up to 40% of the area of windows is taken up by the frame, posts, transoms and Georgian/feature bars — meaning that with a wall aperture of 1,5 m2 only approx. 1 m2 is taken up by the actual glass area.
Reveals that open out to the room reduce the contrast in light density between the wall and the opening — a transition zone with medium brightness arises in the reveal. This allows you to avoid or significantly reduce glare. A slant that opens to the outside increases the proportion of zenith light on the inside in the lintel area. If the window bank has a significant slant, rainwater drains away better and the outside perspective is intensified. The reveals can also be designed asymmetrically — a number of current constructions reflect different solutions to this issue. Particular emphasising of the reveal can also become an architectural element through, for example, extended reveal boards.