To lengthen a floor or building the first step is to define the area to be modified, by entering a rectangle. Next, a reference point is defined with a further mouse click. All elements or points of elements (e.g the ends of walls), which are located within the rectangle are now moved. First of all a preview is shown and the action can then be terminated with the mouse or numerically in the tool options dialog. In the following illustration the main steps are shown one after the other to demonstrate input.