My son and I live in a one-room apartment privatized in my name. I am divorced and only my 15 years old son and I are registered in the apartment. I want to sell the apartment and buy a two-room apartment but I was told that in this case I would need a written permit for change of housing conditions signed by my son’s father. He refuses to sign such permit (doesn’t want me to live better than he does). Question: Do I really need such permit? In case I do, how can I buy a two-room apartment without my ex-husband’s permit?