Our new neighbour who we don’t know very well started some work last week. I’ve just noticed now that it’s a full width rear extension right up to the shared boarder. There’s nothing on the planning portal but I’ve been told by them that they did get building reg sign off. We’ve not had anything in terms of a party wall agreement. It’s not clear where they intend to tie in the extension. I’ve just been told ‘up to the fence panel’