It is a matter of personal choice to use the HELOC.  

@Igor A.What data should I reference?

If this contractor is known as being reliable, or was referred to you by a reliable source, then you've already taken a load off your shoulders.

My friend who recently bought a rental referred me here when I inquired where he learned from. 

Part of his development has what we refer to as the donut. 

I think that if you have a choice of making it into a third bedroom and private bathroom with its own entrance.

If it is not a bridge loan you are referring to I am not sure they will do that. 

There is no one way and it depends also on how you choose to operate your business.Monthly rent...dependant on property, market drivenUtilities....specific to property and marketsinternet, cable....market drivenTenant or landlord costs.. market and landlord choice

@John Lee I have an insurance agent that I can refer you to thats quotes are unrivable. 

The best choice we made was performing full inspections, and asking the owners to fix the items discovered.