Yes, and it's the time/cost/interdependency of these details which can be really hard to illuminate to the client...
One of my old teachers worked for Jennings. He reckoned that if weather was amenable and all stops were pulled out, they could hand over a single storey project home in a hair past six weeks.
Of course, the downside of that is everyone else not understanding why theirs takes longer!
Cheers, Adam.