I live 4 houses from the bottom in a row of terraced houses. To the rear of the houses there is a wide back alley which was used for delivering coal back in the day. All but the bottom 4 houses (mine included) have extended their back garden walls either into or completely over the shared alley. I would like to have a larger garden and would like to do as every other house up from me has done and move my wall in line with theirs. Absolutely no one would be inconvenienced by this as mine is the last house with the wide alley. All the houses upstream have already done it and the houses downstream would not have the width of their alley compromised. I have made a SIM application from the land registry and have found out that the land is not registered. I have also discussed this with my neighbours and they don't mind. I'm a bit nervous about going ahead as I don't really know whether I'm allowed to do this or not. Any advice that can be given would be gratefully received.