Our project is a hotel for which all guestrooms are being manufactured as modular units. This will certainly save waste, and we are interested in pursuing Option 2. However, it isn't clear if in this case we only calculate the waste leaving the site, for foundations, roofing, etc., or if we need to account for the waste being produced at the factory as well. We are a little concerned about this as the manufacturer has already said that they have never tracked waste. 

Does this differ in v4 and v4.1?

Also, is there a calculator for this option?