Thank you for your responses.
My background is in architecture, I am a big Vectorwoks fan, but I spend some time working for a door manufacturer.
Regarding the standard door hardware feature, while this feature is excellent I doubt if it will give me enough control of, for example hinge positions. (and maybe even 3d geometry).
Complexity could be relatively simple, for example a lockcase in 3d could be quite complex, but all that is important to me is the external shape, the cut-out in the door and that it get's picked up on a schedule. I think it could be a symbol that adopts a standard position in the door.
I will do up a typical example, I see you're on LinkedIn. I'm not real into forums.
By accurate enough for fabrication I mean something I can convert to a .dwg and send to a CNC router. This might sound complicated but it's not. As I say it doesn't need to be super complex, but the beauty of parametric objects is speed of variation. You mention different door styles I don't mind producing a script for each format i.e. single leaf, leaf and a half, etc. but to be able within those parameters to alter sizes would be big.