PD loft conversions setting back when no eaves?

[Flipjango]

We are planning a PD loft conversion. The house has a gable front and back, and the roof apex runs front to back, sloping side to side. At the sides there are no eaves, none at all. The roof slope ends at the brick wall, and then there's guttering along the wall. The architect tells me we need to set the dormer back 200mm from the eaves and no further forward than the house wall I believe, but as there are no eaves it's contentious where that would be. He's useless and has no idea where he can put it. Can anyone help?

This is the side wall of the house (if you zoom in over the chimney you can see where the roof ends right on top of the side wall)

 

[^woody^]

Every building with a roof has eaves, and it has actually been defined within the GDPO guides.

In this context, you measure from the edge of the tiles 200mm up the slope and start your dormer there.