By Dennis Collin
How do I control where Revit measures its dimensions to?
The TAB key on the keyboard provides alternate selections not just for selecting objects but also for dimensioning placement as well.
The options in the task bar do help to dimension structural elements like walls, but for items like pipework and round ductwork, the TAB key is an essential to snap to secondary references.
This is useful either for setting clearances between services and building elements or for measuring non square buildings as per the image below. Use the TAB key to snap to wall intersections rather than the default face options.