If you did that for your son, it would make you a great parent. I'm just stating my experiences, having not had any financial help from anyone on my side of the family. If you come from a great family that can help support you while you're getting started, then maybe you don't need to wait till 40. That said, rent free may backfire. If I were ever in that situation, I'd "sell" them a "mortgage" on the property, at something like 50% to 75% of the best offer they can find. Don't do anything official. But make sure that they're paying off the "mortgage", so they have an incentive to work, and won't feel like they're living on your charity. Meanwhile, get them really involved in "helping you" find suitable investment avenues for "your" cash. That "mortgage" is actually just an investment/savings account that you're looking after for them. By the time their children grow up and need their own place, they'll be able to afford it outright from the investment account despite what jobs they have, and the cycle continues. My grandparents did something similar for my old man. They charged them board to live with them instead of renting. And then when they finally bought a property, my grandparents gave them all the cash that had been paid to them as board.