When is it ok to use Construction data in lieu of Design data when modeling under Appendix-G? Appendix-G states that the proposed design is based on the design (contract documents), and does not say to use submittals and as-builts (construction documents). Well, let's say the Architect didn't specify enough performance data on the windows. Let's say he/she only gave a U-value and not the SHGC in their specifications. I think you could use submittal data at that point to fill in the missing information. Just keep in mind that submittals are for cursory review, and may not be what is dropped off the back of the truck on the jobsite. So there is a due dillegence step to verify actual windows installed performance values. And on that note, it is very risky and expensive to allow an open factor such as the SHGC into the design.