You can't expect your teens to keep a spic and span apartment unless they have been used to doing the chores while they were still in your house. That is why they should be trained to do them while they are still younger.   When the time comes for it for them to move out, all you can do is help them out prepare their place. You can remind them at the start but that's about it. All you can do is to tell and make them feel that you are just a call away. You cannot do all the cleaning even if they asked you to though. You should let them do the chores themselves. But then if they need some advice you should be able to give it to them too especially at the start. If they need a bit help you could also lend it to them once in a while. This way, they will also learn how to live on their own and be responsible individuals.   What you should never do is arrive to their apartment unannounced. You should never go there without their knowledge either. If you expect them to become responsible, you should also give them room to make mistakes and to learn on their own. That is why you should also give them some space.