Driftmark - How Far Ahead Do You Have to Be of Production?

For something like Driftmark, how far ahead do you have to be of production in order to get that up and running? I think we built a big courtyard on the St. Michael's Mount Island five weeks before we were actually shooting. And I think that it was probably three or four days shooting maximum. So again, it's a lengthy, lengthy process for a few minutes on the screen.