Revit is a powerful program, yet when not used correctly, it can create unexpected problems. It has become apparent to me that it is essential to create a level for every different floor height., even if there is only a 1′-0″ level change. That way, all windows and doors, when put it at the proper level, will appear correctly in elevations and sections. Roofs and Ceilings will appear relative to their levels too. It’s easy to forget to adjust for a height difference when there is no level for that sunken living room, or wing of a house that is 1′-0″ lower then the other. I have just experienced this first hand. A client of mine decided that rather than create a level for that 1′-0″ lower floor, he put all walls at Main Floor -1′-0.” He also had to put the slab at Main Floor -1′-0″ and then had to calculate the ceilings at Main Floor -1′-0,” etc. Consequently, we started finding doors that were sitting 1′-0″ above the floor on that lower level. That’s because it’s so easy to just go around an plop doors in without thinking about where they are going in space.
On the other hand, I have stopped putting Levels at every different parapet or roof height. I use one or two only. Most roofs and ceilings are relative to the floors (levels) they are on. In elevations, I end up hiding many of the level symbols, and instead I use spot elevations to show parapet heights. I don’t know if this is the standard, but it works for me.