Building line
A legally fixed line determining where buildings may or may not be placed, often to secure roads, public space or urban design.
A building line defines the limit beyond which construction is prohibited or must align. In Swiss cantonal and communal law it is used to reserve space for roads, railways, watercourses, squares, sight lines or coherent street fronts. It may be stricter than ordinary setback rules and is often shown in a plan. A project crossing the line generally needs refusal or a specific exception if available. Because a building line restricts use of land, its adoption and modification require the planning procedure and respect for proportionality and compensation rules where applicable.