Loft extension query for the smart!

johjames

Hi All,
I'm hoping that some MSE wisdom can help us here!
We're in a bit of a pickle and I would really appreciate the opinion of those more knowledgeable than myself.
We're planning to build a rear dormer loft extension to our mid-terraced house.
Our neighbour on 1 side already has a loft extension, which is shown in the attached photo.
The cheek of their extension is built to the middle (or thereabouts) of the parapet party wall as shown in the photo's.
We would like to build the cheek of our loft extension to the middle of this parapet party wall and we had originally planned to build up the parapet party wall in brick, to separate our 2 extensions and to act as the cheek wall.
We had thought that this would be possible as our neighbour had told us that their extension was set back from the parapet party wall. I only just found out that this isn't the case, after visiting my other neighbour and looking up at our roof from there, as you can't see this detail from our garden. Of course I should have checked beforehand rather than just taking my neighbour!!!8217;s word for it, but we are where we are.
So my questions are (a) will it still be possible for us to build our loft extension to the middle of the parapet party wall and if so, how would we do this? (b) can we join our loft extension to our neighbour's, even if they do not want us to do this? We!!!8217;ll of course talk to them and see how we get on, however he's a landlord and doesn't live there, but I!!!8217;d like to know our options (c) Do you think we'll still be able to extend the parapet party wall upwards in brick as we'd planned?
Apologies for the lengthy post and thanks for helping.
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