If your resulting roof is getting a non-centered ridge or a similarly offset shape, it could be that you used a combination of the Pick Lines tool and the Pick Walls tool when you sketched the roof. These two use their offset properties differently. The former places the reference level of its lines precisely at the specified height (which is the referenced level plus the offset value), while the latter places its lines reference levels at the top of the wall, with the Offset value bringing the eaves down below the tops of the walls. In other words, with Pick Lines used on a wall and with a 2-foot offset, the resulting eave's edge will be at the top level of the wall; whereas with Pick Walls used on a wall with a 2-foot offset, the resulting eave's edge would be a little lower than the top level of the wall (you can do the trig with the roof pitch to figure out how much lower if you wish).
Put simply, remember that Pick Lines and Pick Walls act differently, so use either one or the other in simple roofs like the one in your photo. Only combine them in special cases when a combination is specifically needed.
