The local inspector would know. We run vents on the outside and through the roof sometimes here. And of course much of the older Seattle homes have the plumbing outside the walls.
Those all go through the roof under the eaves and are at least six inches higher then the roof. More like 12"
Vents can't daylight under a window.
The whole idea is to get the venting up high where the winds can blow it "away" from your home.