There is a "boxed cornice" or "boxed eave" on both the dormer and the main house roof and it includes all of the roof overhang construction including the soffit. Some traditional ones are shown below.

When a boxed eave cornice intersects with the raking cornice (or rake) the soffit below the overhang is awkwardly exposed. There are several ways to deal with this issue.

In the photo at the dormer, the soffit stops at the end of the dormer so the eave trim simply intersects the rake trim. The termination of the soffit before it gets to the rake is not particularly attractive but in this case it is painted a dark color and is difficult to see. This would not work well on a different style house IMO.

In the photo at the main house, the entire cornice (trim and soffit) continue to the face of the rake and instead of turning and running along the face of the house, the end of the cornice is covered as simply as possible with a "porkchop" rake trim.

Another way to deal with this condition is to "return" the end of the horizontal eave/cornice shape along the face of the rake wall, a detail used by the Greeks and all who followed and frequently modified to make the construction easier. See the original and modified methods below.

Cornice construction:

Classical and Modified Cornice Returns:

Here is a link that might be useful: the book you need

This post was edited by Renovator8 on Fri, Feb 7, 14 at 9:10