There are too many ways you can have bad neighbors.
You can have a neighbor who are rawdy and rude. You can have a neighbor who leaves dogs loose and poop on your lawn. You can have a neighbor who's kids are thieves. You can have a neighbor who spies on you with binoculars behind shades in his(her) bedroom and report to the county that you are building a pool and retaining walls without permits. And last but not evidently not the least, you can have a neighbor who has the intention to prey on young children...
That's why some people don't want to have neighbors and live in the countryside.
Now, back to your problem. Base on a scale of 1 to 10 (or 1 to 5), rate the seriousness of this situation to you. Maybe when the construction is over you will not be objective to the pool and walls. And also on a scale of 1 to 10, rate how much resource you are going to spend to handle this. Let's say 1 is minimal effort or $100 or less, and 10 is a court battle of 2 years and $10000 lawer's fees(depending on how much detrimental effect on your real estate value) If it is simply a code violation, then sooner or later they have to take it down and pay the fine. But if it's not forbidden then you have to live with it (you may be entitled to some compensation, as I said before, but I am doubtful). In any case you are going to have an unfriendly neighbor and you have to handle this. Well, to handle unfriendly people is just part of the life.
You can have a neighbor who are rawdy and rude. You can have a neighbor who leaves dogs loose and poop on your lawn. You can have a neighbor who's kids are thieves. You can have a neighbor who spies on you with binoculars behind shades in his(her) bedroom and report to the county that you are building a pool and retaining walls without permits. And last but not evidently not the least, you can have a neighbor who has the intention to prey on young children...
That's why some people don't want to have neighbors and live in the countryside.
Now, back to your problem. Base on a scale of 1 to 10 (or 1 to 5), rate the seriousness of this situation to you. Maybe when the construction is over you will not be objective to the pool and walls. And also on a scale of 1 to 10, rate how much resource you are going to spend to handle this. Let's say 1 is minimal effort or $100 or less, and 10 is a court battle of 2 years and $10000 lawer's fees(depending on how much detrimental effect on your real estate value) If it is simply a code violation, then sooner or later they have to take it down and pay the fine. But if it's not forbidden then you have to live with it (you may be entitled to some compensation, as I said before, but I am doubtful). In any case you are going to have an unfriendly neighbor and you have to handle this. Well, to handle unfriendly people is just part of the life.