How can I show the line of a roof or slab overhang in a floor plan?

This post is regarding one particular query, you can see the full list by clicking here.

The best way to show the elements on a level above, such as roofs, slabs, or voids, is to set the level that the element is on as an underlay on the floor plan and then use the linework tool to change the style of the line you want to show.

To do this, in the properties of the floor plan, go to the Underlay setting and choose which level you wish to see elements of (usually the one directly above). Change the Underlay Orientation to Plan. You will now see the plan of the level selected shown as thin grey lines. Next, under the Modify tab select Linework Tool. Choose the style of line you wish to show. For example, drawing the outline of a roof over, you may wish to use a dashed line style. Then, simply click on the thin grey lines that you wish to show and they will change to this new line style. Now, when you go back and change the Underlay setting to None, all of the thin grey lines disappear, however, the lines that you changed the style of will remain.

It is important to use this method as opposed to drawing detail lines because it ensures the lines shown for elements "over" are always accurate. It is easy to change the outline of a roof but forget to update the lines on the plan below showing its overlay. This way, you don't have to!

One final note, Underlays are not always predictable, so to see elements on a level above sometimes instead of choosing Underlay: level above, Underlay Orientation: Plan, you may have to choose Underlay: current level, Underlay Orientation: Reflected Ceiling Plan.