You could simply say "I'm sorry, I can't add any additional people to the lease" and leave it at that, and look out the window when she moves the sister in anyway.

This was also PAST the window written in the contract when he was allowed to back out without penalty.The next day, my bank notifies me that the check didn't clear because his account was closed.

I found out from the realtor that it had been under contract and the inspection revealed in so many words:-there is an underground storage tank (I'm assuming underground here)-"water intrusion" around window and exterior wall. 

Whatever you come up with, make sure it's easy to read while in traffic.I see so many cars where people actually paid for a window wrap which can only be read standing next to the vehicle while it's not moving.

Once those two week go by, the activity starts to dwindle and the window of opportunity, to get offers at or above list price, starts to close.

If it's an older property (more than about 20-25 years), have any of the windows been replaced with more efficient ones? 

Consider many elements, from roofs, to windows, and interior elements can be near the end of their useful life in older fourplexes (in my area many were build in 80's). 

My other thought is to sell it, but sense I'm renovating this property twice (same idea, flooring, cabinets, vanities, paint, garage door, windows, etc.)

Already has egress window, closet and access to the hallwayNeighbors are paying $5500 to have a couple dead trees and other landscaping removed by a contractor to improve the aesthetics of the neighborhoodI am headed back over Thanksgiving to further inspect the property as the descriptions above are all from a conversation with my father.  

Hi BP, I have been looking for vacant homes and have came across several that have a permit sign in the window.