As  @Ned Carey indicated you need to have room to build extra equity through Rehabilitation (adding value).  

Once a Value is established you then evaluate the condition of the property to estimate the amount of Rehabilitation work required to bring it up to Market standards.  

When asked what I do, I simply stated:  "Residential Leasing" and "Residential property rehabilitation".  

As for rehabilitating a partially vacant building, if possible you start with a vacant unit, rehab it, and either relocate an existing tenant or let it to a new tenant.  

Although the decision was largely based on the Rehabilitation Act of 1973, 24 U.S.C. 794, the court remanded to the trial court for consideration of whether a reasonable accommodation could be made, given that the tenant had a mental disability that required her to keep the dog in her apartment.

This investor's time is MUCH more effective in overseeing the rehabilitation process of his or her investments. 

Then it starts to rehabilitate slowly if they have other credit they are handling responsibly.  

Hey BP,I found out that is possible to remove a unit from Rent Control if you do "Substantial Rehabilitation" Substantial Rehabilitation:This applies only to entire buildings.

So here I am, future rehabilitation center therapist, graduating from a graduate program in two years, looking to obtain a FHA 203k loan to move into my own investment property(duplex, triplex, or quadruplex) with only 3.5% down(the terms of this loan) and obtain rehabbing financing.

Instead, the landlord must look at the type of crime, age of perpetrator at time, and history of rehabilitative acts in the intervening time period.