Sometimes the best intentions result in unintended consequences, and you have to accept the good, the bad, and at times with software....the buggy.
One long-requested feature by users was finally added in Revit 2023, as duct and piping systems are retained in the properties of demolished duct and pipe. That way, duct and piping system abbreviations could be tagged on demolition drawings. However, it wasn't expected that this addition would lead to an entirely different issue.
I recently assisted our Helpdesk group with a case in which a customer discovered that when new duct and pipe cross over demolished duct and pipe in Revit 2023, they would connect to each other since the duct and piping systems remain enabled in the demolished elements. This causes sections of the demolished elements to convert into new duct and pipe fittings and make them disappear in the demolition plan view.
This doesn't occur in previous versions of Revit, as system properties would become "Undefined" on demolished duct and pipe and prevent demolished elements from connecting to new elements.
Adding a dedicated 'Demolition" phase (I know, I know, demo is not a phase) before "New Construction" doesn't help matters either. Even when the demolished elements become hidden in the newer phase, they would still connect to new elements.
So what can be done about this? At this point, I can recommend a couple of things:
- Model in a working view with Phase Filter set to "All" to be able to view all the elements for coordination
- When crossing over demolished duct and pipe with new elements, disable the "Automatically Connect" option to avoid connections