Parapet

A parapet is a low wall that rises above floor or roof level at the edge of a building. It is most common around flat roofs and roof terraces, where it defines the roof, offers protection against falls and finishes the top of the facade. In Turkish site language, the word is also used for the section of wall below a window, between the floor and the sill.

What matters in practice

A roof parapet is a technically sensitive spot. Waterproofing has to be turned up the inner face to a sufficient height and the top must be covered with a coping, either stone or metal; otherwise water gets into the wall. A parapet is also a thermal bridge risk, so insulation needs to wrap around it without interruption. Where a parapet acts as guarding, its height is set by regulations, and a railing is added on top when it falls short. Under windows, the parapet height is chosen with furniture layout and safety in mind. How rainwater leaves the roof, through scuppers or downpipes, should be resolved from the start.

Its effect on the facade

The parapet is the last line of a building’s silhouette. A slim parapet keeps a building looking light, while a thick, tall one makes it heavy. In a render, the coping or metal capping at the top creates a sharp line against the sky that strongly affects how finished the facade looks.