Bug reporting is always the big point of Inside the Factory meetings with Autodesk. This year they tried to play on my competitive side, using day by day charts with number of bugs reported by us. Well, I didn’t reach the podium, but I’ll come prepared next time! There are couple of things in Revit that just doesn’t look right, and as of version 2017 – some of those bugs still exist.

I’ve spotted this one working on a partially to-be-demolished basement model, and here’s how to replicate it:

We’ll start with modelling main actors of this tragedy:
Structural slab – Phase created: existing, Phase demolished: none
Shaft opening – Phase created: new construction, Phase demolished: none
And for reference:
Structural column A – Phase Created: existing, Phase Demolished: none
Structural column B – Phase Created: new construction, Phase Demolished: none
Chunk of slab – Phase Created: existing, Phase Demolished: New Construction
In summary:

Now let’s go back to the views. Let’s start with the completed one, i.e how does in look at the end of “New Construction” phase:

Seems about right.

Now let’s go to view highlighting the amount of demolishing taking place (it’s the state “between” existing and new construction):

Lift opening should be marked in red!

So how does it look in the “Show Complete” (end of “Existing”) phase?

In my opinion – this is incorrect. The “void” part of shaft openings for some reason ignores the phase in which it was created… and to make it more confusing, detail lines are (correctly) gone. When we look deeper, we see that the model element of “Shaft Opening” category is in fact gone… but it’s effect (void in the slab) is showing preemptively.
As I mentioned before – I might be wrong, maybe I’m missing something – please let me know.
And if anyone is interested with the solution I came up with – that’s what chunk of slab is showing – we’ve started modelling separate ones to simulate the effect of creating a new opening in an existing slab. Detail lines were placed manually.