@Jordan Rodick  Selling real estate in Illinois without a license is punishable by a $25,000 fine for each offense. 

The legal process for dealing with criminal actions or violations of civil law is not speedy and more often that not in this type of eviction situation, you'll be dealing with someone who is "judgement proof" so even if they are (eventually) punished for a criminal action, you're unlikely to ever be made whole.

@Doug JohnsonI would never do such an arrangement I would charge a tenant if they left early .that is punishable I would certainly not allow their personal situation or family member issues dictate our agreement that was made .

I don't want to punish anyone.

Adus take a special builder that is a sucker for punishment by the city and the tight confines of the urban environment.  

Don't just do it to punish them. 

A landlord found guilty of refusing to rent based on source of income would be guilty of a first-degree misdemeanor, punishable by up to 180 days in jail and a $1,000 fine. 

A violation is punishable by up to 5 years in prison and $250k in fines. 

None, yet we are legally compelled by threat of significant punishment by the state to provide ongoing services to nonpaying tenants while we burn our life savings paying for property taxes, mortgage, maintenance, insurance, etc etc.  

If your area doesn't punish converted garages but rather extends the value of the original sqaure footage of the home directly to the converted garage space, that can be a great play.