In the next two posts I'll cover two parameters and a feature both of which can solve the same problem in different ways. This post is on the "Cutoff Level" and "Cutoff Offset" properties we find in Roofs.
In the strata of Revit features the Cutoff properties were introduced somewhere in the cretaceous. Like a vestigial tail you might have wondered what purpose it serves. You may have even set some values and not seen any visible change or got an error "Cutoff Level cannot be below bottom of roof". Scary.
Essentially what these properties do is cut back or trim (perhaps better terms) a footprint roof.
Below is a progression where a roof is created, the Cutoff properties set, and then a third roof added to create a Mansard shape.
Voila! There are other ways to do this that may or not be less steps but perhaps easier to understand. I'll cover that in the next post. BTW if you are developing an in-house test to plumb the Revit knowledge of your hiring candidates this could be a devious inclusion.