Estimating Rehab costs from out of state

[Diana B.]

I'm setting up a strategy for investing (buy and hold) out of state, and the one area I'm not clear on, is estimating rehab costs from a distance.

I will be in my farm area to build a team, interview GCs, find trusted contacts and visit properties. However, I will mostly be out of state and I wanted to hear from investors here on how you get a good rehab estimate. 

For example, once you find a property that requires your approximate desired amount of rehab, do you request your trusted GC (or two?) to go down there to give a better estimate before you put in an offer?

Thanks!