I dont think you can change someone easily or quickly at this age. Your aim should be to tactically make him buy a new house and make him independent. For eg: You could discuss how buying a house is such a good investment, or XYZ location is really a hot location now a days to buy property. You can help them in finding the house and if their is lack on money - at that instant say that let me see if i have some savings i can help you with instead of offering your gold beforehand. There is a long way to go. Talk to your mom first, maybe that will help.