Hi There,
Yeah did wonder is this thread would be resurrected. Phew, I do appreciate it.
It is an odd one, I live in a off-street shared drive, almost like a private road in a detached bungalow. The dormer will hardly visible, if at all, from the road, I could work out angular calculations of visibility if need be. Only one neighbour, who will not object. At the back is a railway line so the houses on the other side are too far away to matter.
Probably only require 400mm, though more would be better if possible. The pitch of the roof is too shallow currently to add a dormer with height, so either a raised ridge or lower the current ceiling. Only the portion of the dormer would the ridge be raised, and for the entire dormer ridge to be enough room, if the entire house this would cause carnage.
I was wondering what Luke did in the end, sounded a bit like my conundrum.