Do it very intentionally, not just for the sake of scaling up, but to get better quality or easier to manage properties that will replace lower quality or harder properties. 

You need a repair partner who can get out immediately and has quick access to replacement parts (if not already in stock). 

And you do not technically have to replace debt. 

@Michael ReilmanKohler and American Standard both make great toilets, but Kohler toilets have unique parts that you can't replace at Home Depot or Lowe's.

Same with a refrigerator replacement, HVAC system repairs, etc.So, I am back to echoing Jaycee: first, don't be discouraged because someone else says to avoid a part of town.  

Prior to inspection I replaced one outlet cover.

During this renovation period would you, as the lender, want an Actual Cash Value or Replacement Cost policy in place?

Especially, after the storms and the loss of the projected income and they have no way to repair or replace everything that was lost.  

In my round-up note as we moved out, I mentioned that the ice maker in the fridge hadn't worked in many years and the model was known for issues so we just never replaced it. (8 year old fridge.) 

Dwelling (Building coverage)The limit should be based on the Replacement Cost of the building (cost to rebuild withthe same kind and quality excluding the foundation)2.