Legal Question in Construction Law in Illinois

Re: mechanical lien

The answer to your question lies in the agreement between you and the ex-girlfriend, at the time you made the agreement. A mechanics lien has to be based on an agreement that a court would recognize as legally valid, though that doesn't include writing it down.

So the question becomes, at the time of agreeing to do it, what did you request from your ex as payment, and what did she agree to pay? If the answer is that you were doing it for free in the interests of the friendship/relationship, then you have been paid in full exactly what was offered, so you wouldn't have a lien right. However, if she agreed to pay you something, and didn't, then you have a lien right just like any other contractor would.

Keep in mind there are also mandatory disclosures for residential projects, and other technical requirements, and you might be obligated to produce those, if the project qualifies for that.