Advocate Faiz Syed was asked what is the opinion of Islam on joint families and what should a man do if his wife wants him to live separately but the parents of the man insists him to live together.
He said that Islam believes that when a husband marries he starts a new family and he should live separately because there are many ethical and religious matters. Wife is mahram for his father in law but cannot talk and live with the brothers of his husband which means separate house will be better for them.
Advocate Faiz Syed explained that the relation between wife and mother in law results in verbal fights and hatred so it is better to live separately.
https://www.youtube.com/watch?v=x5ICnlVAcSo