Using the brrrr strategy how do you calculate arv?

[Rickey Davis]

I just finish reading the Brrrr book by David Greene. One thing I don’t fully understand is calculating the arv. Now do you do this after you get a house under contract and go in with a contractor and figure out what you want to rehab with an appraiser present or which is the best way to step by step come up with the arv. Just want to fully understand because this seems to be most important when seeking a deal using brrrr