Your goal should be to move out as soon as possible. Even if this means a drastic change in lifestyle and standard of living. I think parents should wean their children off of financial support. Cutting them off completely can often lead to resentment and larger issues. I would suggest by starting to have the child take over certain expense categories. Start with discretionary expenses, then everyday necessities like groceries and gas. Then get to more major expenses such as rent and insurance. The key is to start with small expenses that occur everyday such as food because the everyday repetition will train them to make spending decisions. Getting them to financial independence is important, the soon you can accomplish that the better for both parties.
From the child’s point of view, I think it it would be best to offer to take over the certain smaller expenses to start. Offer to do the grocery shopping, pay the utilities, cell phone plan, etc. Then once you are making enough money, move out. Your goal isn’t to pay them rent, it’s to have your own place. Also show them you are responsible by making efforts to make extra money through odd jobs and part time work. Make sure they know you are being aggressive in saving money. They’ll be more willing to support you knowing that you are actively making progress to be independent.
Many would argue that living rent free with your parents is a good way to save money. This will only stunt your long term financial growth. Not to mention, your “savings” is really just imposing on and taking advantage of someone else. Living with a friend or relative rent free is equivalent to going to a restaurant and not tipping the waiter. You are taking a valuable service and not paying for it. Most waiters will probably never get the chance to call you out for a bad tip, but that doesn’t mean they don’t notice and aren’t upset by it. Similarly, your parents or friend may be too polite to complain about you living with them but trust me, sooner or later they will feel like they are being taken advantage of.
Even if your parents live here …
… and you can only afford this
You need to build your independence and live within your means, not your parents.
If you want to read more about the long terms effects of getting financial assistance from parents, there is a whole chapter about it in my favorite book The Millionaire Next Door.