I had my DD in our current apartment two years ago. i'm pretty good friends with my neighbors and they knew well in advance we were having a homebirth. The girl who lives upstairs said she had her ear pressed to the floor during DD's birth and was cheering for me when she heard the baby cry! :P If you want to have a homebirth, have a homebirth! If you want to talk to your neighbors, go ahead, but you don't exactly owe it to them... the aforementioned neighbor has the loudest sex of anyone i've lived by and she never asked me if it was okay. Lol!