Just curious after reading some really good suggestions.
It's been pointed out 1 and 4 are most likely bathrooms. Which would make sense as far as plumbing is concerned. Do you think they are on reddit, taking a dump, watching you? Brushing their teeth admiring your tan?
You ever thought they might think you are watching them?
Why not go talk to them and see if y'all feel mutual and come up with a solution that would satisfy both parties? Might even get them to help pay for some of it. Looks like y'all have some nice houses and probably yards as well. Even if you are in your right, you might want to include the neighbor. They may also have a good idea and want the same thing.