We are an end terrace and NDN is currently extending the back of their house. I think the extension will fall into the permitted development so they won't need planning permission. We have no idea though of what the extension will be like! We've not been shown any plans and possibly more crucially we haven't signed or been given a party wall agreement. I've had a quick look at the act and think it could well apply (extension will be tiny if more than 3m away from our foundations). But because we've not seen any plan's we've no idea and no idea how far down they'll have to go for foundation's. I don't particularly want to fall out with them but I'm getting twitchy! Do I need to be worried and taking some action? Thanks.