Hi, Background ========== I live in a row of small detached bungalows, each about 3 to 4 feet apart. (Just enough room between them to give access to each back garden). All of these bungalows in our road are either in the middle of getting extended or are mid planning permission etc. Problem ======= Anyway, my neighbour has pretty much finished his building work/extension and he has a problem, which now, is also my problem I guess. One of his new bathrooms, the one furthest away from his sewer, backs onto a wall which is on our boundary. He says that Building Control has told him that he needs to install a new soil stack and vent it to the outside. This is a downstairs loo. He will have one other one downstairs and also one upstairs. He has asked whether I would be ok on him having this come out of the wall facing us and projecting up his wall on the outside of his building, but in the my "air space" of my alleyway. I am not very happy about this without at least seeing if there are any alternatives. Questions ========= As this is the last loo on his system, does it have to be vented to the outside? Why can't it just be vented inside like his other 2 loos? (3 in total) If he does have to have a vent pipe outside, can it be a smaller diameter than the one he is proposing of 4 inches? How can any smells coming out of this stack be handled without having pipework going all the way up the wall and up over the gutters and eaves, causing an unsightly mess? Any other advice for us? Please help if you can. It would be much appreciated. Cheers.