This week our own Jordan Mussett explains using the Project Base Point in Revit to export AutoCAD background drawings.
Many Revit users get themselves in hot water when it comes to providing consultants and sub consultants with AutoCAD Backgrounds. In the images below, the Project Base Point does represent the 0,0 point in AutoCAD.
At its simplest, Revit has a point that it doesn't tell you about. There is the Project Base Point, the Survey Point, and what I like to call the original origin. The original origin reveals itself in the following way. When the Project Base point is unclipped and moved, the 0,0 point in AutoCAD is now where the Project Base Point was. Another way to look at is, if the Project Base Point is unclipped and moved, the 0,0 point in the AutoCAD export is now different than where the Project Base Point is in Revit. This is going to be something that more likely than not, the consultants are going to point out to you by asking, why is 0,0 over here? In the pictures below, the Project Base Point was unclipped and moved. In AutoCAD, the 0,0 point stayed where it was.
So what is the safe practice? At the outset of a project, turn the Project Base Point on and use this point as your intersection of two grids preferably at the corner of the building and go from there. That way everyone linking origin to origin will be good to go and everyone receiving AutoCAD exports will be seeing a 0,0 point at the intersection of two grid lines.