Before you can edit objects on a plan, you must select them. Use the Selection tool () or the Utility tool () to select objects on a plan. You select visible objects by fencing the area in which they are located. For example, if you have a slab opening (on the Mesh Input layer) in the middle of a slab, fencing the opening selects both the opening and the slab area because the rectangle crosses the slab area and surrounds the opening. If you want to select just the opening, double click on it. You can select any single object by double clicking on it. To add objects to the current selection, hold the <Shift> key down as you select.