Just found out from the previous owners of our house (we've lived here 2 years) that there was another window in the darkest room of our house but neighbours asked if it could be bricked up as it overlooked their garden. Previous owners agreed (no idea why 🫣) if neighbours paid for it to bricked up/ replastered inside. Same neighbours still live there. Can we legally open it up again into a window? It would absolutely transform the room if more light could get in but would no doubt piss the neighbours off.