Yep, not the top roof. Some 50? years ago a rough addition was added to mine (before i arrived) and the kitchen roof on mine is a ground floor ceiling. The semi-detached next door put a 2nd level on their back part and that's when the leak appeared in my kitchen ceiling.
It's not a really big deal as it only leaks in a relative torrent and a pot works overnight. Just a nuisance and the fact that the builder is not keen to fix it for free is the most irritating of all. Not surprised, just still an irritation.