I have a neighbor over the room where I practice. My wife in a home office. I’m not really into rules but courtesy still applies. I don’t play at a volume I can’t sing over without a mic unless she’s out of the house. If it gets loud she either closes the door or calls me on my cell phone, usually because she thinks I’m singing too loud. In my mind, I’m not too loud if I can hear the phone ring. Still, there’s more than one reason for the volume control on the guitar and I can always work on modulating my voice. If I can come to agreement with someone inside the same house, courtesy and compromise should lead to resolution of the conflict with a neighbor.