I agree with Marcmeis...it sounds like he has some "responsibility" issues. If you've got doubts, it's time to have a serious talk with him about what you want for your future.....if his "dreams" are different.....it's time to move on! Don't get caught in the middle of his misery! Just because one's credit is bad now doesn't mean that one can't work to greatly improve it. Been there done that and with a little discipline, it's not so hard. Don't let him bring down what you have worked so hard to gain. If he wants a house so bad, let him get up and work for it equally along with you.
If you need to ask the question, and that he will not help you at all but you have to do everything then that should tell you what to do. If he has no job why buy a house you alone would have to pay for, make sure his name is not on it, I would set some ground rules and if he still did not want to change then he must not want to help much. If it were me I would say the free ride is almost up because there is only so much as a person that you can do and only so much hurt in your life time you should or have to take. I will pray for you.
If your gonna buy a house let it be the house of your dreams.Let me be real with you if you buy that house not only are you gonna be left with the bill also with the responsibility of his mother.Get an apartment and tell him the only way he is coming is if he has a job.If you are out 8hrs a day he needs to be as well.
The mere fact that you are asking the question tells me you already know the answer. When it doubt, there is no doubt. Would you have asked this same question 7 years ago?