The importance of window placement
wooden jamb, header and subsill (I-shaped, glulam or composite insulated beams), determine which position is best for fixing the window and connecting up to the insulation plane. Ne ertheless, depending on the intention of the design, it is also possible to set the window on the inside of the wall (e.g. within the installation plane of a timber frame wall) or very far on the outside, even flush with exterior wall surfaces (fig. 4.17). In all of these cases, it is necessary to determine the thermal bridge value at the window edges and enter it into the PHPP indo orksheet. When the indo s are set flush with the exterior wall surface, protection against driving rain has to be considered. The position of the window in the wall is closely related to the amount of shade created b the re eal. Setting the indo deep into the reveal leads to a considerable reduction of solar gain - this may however be desirable in summer. The opposite occurs if an exterior position is chosen. However, the reduced depth may be cause for a creative conflict if the necessary shading device is to be integrated into the wall. The space for a suitable connection of the insulation is simply not available in these circumstances.
Window reveal design In order to ensure a continuous layer of insulation around the building, the outside of the window frame should be wrapped with insulation. In refurbishment projects this detail solution changes the position and appearance of the reveal considerably. If the openings are set out on a grid, displacements occur in the facade layout, which are frequently difficult to put right. Angled window reveals on the inside and outside can improve the solar gain and daylight conditions. There is great leeway in this regard since the isothermal lines are diverted towards the window here anyway (fig. 4.19 b). The systematic use of this strategy provides new opportunities for the facade design (fig. 4.19 a). Integration of solar shading systems The development of the window details should also include the constructional and creative integration of shading devices. There is a range of ready-made system solutions for some situations. In some of these, the position of the shading device forms the basis for the further development of independent design elements, such as the window frame (fig. 4.20).
4.16 Comparison bet een an unfa ourable left side and a favourable (right side) position of a Passive House window in a solid construction (top) and a lightweight timber construction (bottom) 4.17 Refurbishment of a single-famil d elling in Kolding DK 2010, Sofie Thorning. The building, including the roof, has been wrapped in a new skin made of glass fibre reinforced PVC panels. The same material has been used for the frames that are set flush with the exterior walls; fixed glass is used in all other transparent surface areas. a elevation b detail section, scale 1:20 4.18 Multi-famil d elling in Wolfurt A 2001, Gerhard Z eier. Solid construction ith facades made of prefabricated timber frame elements; the windows are placed in the installation zone, flush with the interior surface. The window frames are made of wood; the casement has a core insulation of PUR rec clate. a elevation b detail section, scale 1:20 4.19 Refurbishment of an office building in Bozen I 2006, Michael Tribus Architecture. The angled window reveals are a creative measure to improve the light conditions inside. The windows are installed in the insulation plane. The thermal bridge at the window-to-wall junction is minor despite the reduction of the insulation thickness. a elevation of the facade b detail section c illustration of isotherms 4.20 To n terrace houses in Munich D 2006, Rainer Vallentin. The window frames protruding from the facade are not only a special feature, they are also designed to incorporate a roller blind ithout reducing the thickness of the thermal insulation. There are no thermal bridges at the windows. a elevation of the facade b detail section c illustration of isotherms
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