I live on the 3rd floor and they are on 4th. We both own our houses. They have another house in the city center, they stay there more often and come to our building for 2 days a week , but since it’s holiday season they moved here permanently for unseen future, and I’m already losing my mind after 3 days. They got a 12 year old kid, and a new-born baby. The 12 year old is still acting like he’s 3 year old. Running, moving stuff and especially stomping all day , and he has this f*cking marble which he throws it on the floor from height first thing in the morning when he wakes up and makes a lot more noise than stomping . His parents are not warning him. He’s not autistic and doesn’t have any disability. I’m working from home and my productivity is noticeably went down this week.
I’d tolerate to running sound of a 2 or 3 year old kid but he’s almost a teenager ffs. Even the new-born baby doesn’t make tiniest noise.
I prefer to solve this in more civilized and most efficient way. Open to all recommendations.