I'm waiting for an invoice with a breakdown of the cost to see how much extra he's doing besides just the furnaces but the guy seems to think the plumbing inspector is going to make him change a lot of stuff at the property. 

For example, my lease says (in part): "Tenant shall be charged for repair of drain blockages or stoppages, unless caused by defective plumbing parts or tree roots invading sewer lines."

Doing some electrical and plumbing upgrades in the next 2 weeks to get it safe and in good working condition.

But sticking it out and learning a hard knock life way I learned everything from plumbing to electrical to dcr to dti to ltv .

Roof, electrical, plumbing, sewage(is it connected or does it need an on site treatment).

Have cash available to pay for needed work (plumbing, refreshing, etc.).

@Zack KepesThe biggest challenges are the unexpected things you uncover when you open up a wall; illegal or dangerous wiring, plumbing, framing, mold etc.  

Any issues with plumbing, electrical, structural or any other major issues will likely have to be remedied prior to closing. 

With the multi family, the cap ex could be high due to heating units or possible plumbing leaks .

Back in my younger days, I worked in the trades, roofing, siding, carpentry, plumbing, etc.