Choosing the roof window

Window Installation Height

In buildings where storeys are below 25m above ground level, the distance from the bottom edge of the opening window to the floor should be at least 0.85m. In buildings where storeys are more than 25m above ground level the aforementioned distance should be not less than 1.1m. It should be noted that the higher the window is fitted, the more light enters the room, therefore FAKRO roof windows are equipped with a bottom handle opening system to facilitate the opening of the windows installed at optimum height. The bottom edge of the FAKRO roof window should ideally be situated 1.1-1.4m above the floor level. The recommended distance is 1.2m (bearing in mind that average room height is 2.5m), which provides a lot of light into the room and simultaneously offers an unrestricted view.

Installation of the window at this height allows the fixing of a standard radiator below the window and also allows proper lining construction. Thanks to this proper air circulation along the window glazing reduces the risk of condensation appearing on the window.

The Window Placement

When deciding how and where to place roof windows we should consider an option to use a number of smaller windows placed in different parts of the roof rather than one larger as, thus much better illumination of the room is achieved.

The Right Windows

The choice of roof windows depends on:

• The glazed area and the type of the room
• The correct amount of natural light in the room is decided by the proportion of the surface of the window’s glass area to the total floor area. In the case of habitable rooms this proportion should be at least 1:8, and in other rooms where natural light is needed because of their function — at least 1:12.
• The pitch of the roof
• The positioning of the chosen window also depends on the roof pitch
• The lower the pitch the higher up the roof the window should be

Installation on Rafters	Installation Brackets

• FAKRO roof windows are equipped with universal brackets, which allow installation either on trimmers or on rafters. Installation of the window at a chosen depth means that the milled groove marked with N, V, J letters is level with the top surface of the battens
• We install windows on rafters when the window width matches the spacing between rafters, it ensures stability of the construction and the durability of the connection. Installation on rafters is recommended especially when we replace old windows (in already existing roofs) with new ones or when we install big windows
• The roof window is installed on trimmers when the rafter spacing is much bigger than the window width. When installing on trimmers we can move the window horizontally to better adjust the place of installation in relation to the roof material profile

Installation Brackets	Installation on Rafters	Installation on Trimmers