@Mike Reynolds I'm a chemical engineer working in mechanical manufacturing.

That said, if he is a contractor type person who is basically not charging anything for labor, he already has the ability to place a mechanic's lien on the property if he doesn't get what he wants (worst case).  

Mechanic's Lien) or a mortgage which must be paid/satisfied at the time the Loser sells their property.  

Don't skimp on the mechanical inspections!

Typically from what I have seen and heard, older homes in Joliet are usually in need of mechanical repairs especially electrical.

Do you get mad at the auto mechanic because he is making a profit when he fixes your brakes?

Hire an architect to create your full set of CD's (Construction Drawings), with the component plan sections as follows: Architectural, Mechanical, Electrical, Plumbing, Structural, and (sometimes) Civil Engineering. 2.

Another thing to consider is purchasing Home Owner Warranty to cover your mechanicals.  

Got approval, but then the appraiser told them a fence permit was still outstanding (he was wrong) and they got cold feet saying that I could be vulnerable to mechanics liens and/or my taxes could go up do to additional improvements I could do with an open permit/inspection.  

. $48k a door isn't bad if it the mechanicals weren't in such bad shape.