Many references in Bible points out that Man must leave his parents after marriage. Does it really mean that the parents and wife cannot live together in a common house ?
No its specifically referring to sex but some including my maternal grandparents would disagree. Before the advent of modern technology many people did not move far from their place of birth in their lifetime. For instance Isaac did not leave "home" when he married Rebekah. I'm certain there are other examples but caring for relatives especially widows is something which is required of believers. Communal dwellings are common for the very poor and very rich.