Door Jamb to Wall

[nicnicman]

When placing doors on a floor plan how much room do you leave between the edge of a door and a perpendicular wall? As the picture shows, I usually go 4 inches. This allows for a stud and a jack (3 inches) and 1 inches for the door jamb. I arrive at 1 inch because the framers usually add 2 inches to the actual door size for the rough opening so I split that in half--1 inch on each side of the door.



I only use this method when space is at a premium, but I was just curious how do other drafters do it? Should I be adding more? Less?

Thanks for your time.