Depends on when during the entire fab planning process you wanted to place the order. You probably don't want to put the order in until you are 100% certain the site will be built and there is no chance of construction getting dropped for whatever reason, which could go a few months into construction. With the extra months lead time, if you want to be certain equipment will arrive on time, you may need to commit to a purchase before you even know whether all of the necessary construction permits will be granted.