If it was rezoned, chances are they man tell you no and how they were simply waiting for your old house to be sold off and or to become delapitated enough to where they could successfully through Heath and safety laws, force it to be demolished. 

The "perceived" savings are rarely worth the aggravation, and many times they do an incomplete title search, with a title policy that Exempts (section B) unrecorded, but findable liens.

@Steve Vaughan  your a student of the STeven Vaughan scorched earth policy.. .good job understanding that you NEED some MONEY to make Money in real estate.you may want to get a money partner...

I am a broker too; I have abundant capital but have the hardest time finding deals that fit my policy portfolio. 

Anything could happen, I know, but at some point the responsibility for personal safety has to fall back to the tenant. 

In addition to understanding applicable landlord-tenant laws, be sure to thoroughly read through the condominium's governing documents, particularly any policies about renting.  

Just a heads up to check both your Homeowner's policy and Rental Insurance policy to see if you are covered for riot, terrorism, and civil disorder problems.

I don't allow any smoking in my units and have strong language / penalties if this policy is broken.

In St Paul, rentals are inspected by the Fire Department for safety and any flagrant code violations.

Having a loan called or needing a commercial insurance policy can be a bigger deal.