Create and manage construction lines
Construction lines are similar to grid lines because they help you place entities.
- You can create them individually or in an array. For detailed instructions, refer to the creation topics listed below.
- You can snap to existing grid and construction lines (but not other entities) when you select their start and end points.
- Once created, you can move, rotate, or extend them.
- They can also be displayed or hidden at specific levels as needed.
- Grid lines can be used to place entities in both 2D and 3D views, while construction lines are limited to 2D views.
- Construction lines are not associated with a specific architectural grid and, therefore, do not automatically repeat across multiple construction levels.
- Construction line names are not displayed in balloons at the ends of the lines.
Create a single construction line
If you want to create a series of construction lines which form a regular or irregular, rectangular or radial construction line system, the Rectangular Wizard and Sector Wizard are the fastest options.
Create parallel construction lines
This option creates a construction line parallel to an existing one, but of a different length. To use this option, you must have at least one existing construction line in the current 2D view.
Create perpendicular construction lines
To use this option, you must have at least one existing grid or construction line in the current 2D view.

appears you can move
the mouse pointer horizontally or vertically to specify a horizontal or
vertical distance along from the snap point. 



