The window recess is a space between the inside and outside and, depending on the depth and the design, is also perceived as a separate space. Bays and recesses in French windows also define such transitions or spaces. They allow the creation of almost intimate reading or habitation areas that are well illuminated and, equally, can offer a "miniature room" with its own separate character for specific activities. With a corresponding wall thickness, as can be found in historical buildings, these spaces can even be designed completely within the wall level. If the glazed plane is positioned entirely on the outside, a usable space is created on the inside. The glazing can also be arranged on the inside, creating a corresponding (seating) recess in the façade.
From the window to the furniture
Window recesses intended to offer an appropriate use, such as working or reading, can equally be designed as furniture with a seat and/or a table/shelf area through a design that uses timber or other materials. The Fisher House, designed by Louis I. Kahn, in the US state of Pennsylvania, is a successful example of this: Furniture-like timber elements in front of and at window level enable usage options and at the same time, define the window/interior space. This illusion of space in the window is also seen from the outside — the furniture even appears to grow out of the window in places.
If the window protrudes out from the wall level, a bay is created. Bays that are largely glazed can be used as an energy buffer just like a conservatory. Over the course of history, different forms have developed — depending on the cultural, regional or climatic situation, there are open, visible or even more closed variants that allow a view from the inside to the outside. The artistically decorated lattice work (mashrabiya) of bays in Islamic architecture almost completely hides the rooms that lie behind.