When do I include my chosen GC in the process?

[David Troust]

Greetings BP!  I'm thrilled to be posting for the first time, as I'm in the early stages of getting started developing rental properties in the Washington, DC / Frederick, MD area, and have a question about when to include my GC.  

To determine if a property is a potential good deal, I need to know the rehab/repair budget up front, so I can run the necessary calculations with the BP calculators.  Would this mean that I need to choose the GC prior to purchasing the property, or am I able to walk multiple GC candidates through each potential property, to get their bids and compare?

I am focusing on developing a relationship with a quality, reliable GC in the area, and I'm working on getting referrals from colleagues now, but I'd also like to see comparison quotes from comparable GC's.

I'd appreciate input on when to include the GC in the process, and any other choosing GC feedback you've got.

Dave Troust