The construction lines and circles are utilities which help to build more easily the drawings. These entities are inserted only on Construction layer. It can be activated or deactivated at any moment, or partly or entirely erased with special commands. The lines are drawn with the linetype Construction Lines, customizable in the options menu.

With the options menu, the construction lines can be modified by a compass. Thus, for a better visualisation, the construction line will follow the curb given by the compass, as if it was a construction beam.