So we plan to build this plan with the half loft and the rest open below the great room area. My question is that I have seen the truss layout (looking at dave and kim's) plan and understand that will be what the ceiling area looks like in the loft area. So can we just continue with those same trusses all the way to the other end of the cottage as one option? Or do we have to use the open beam layout or a combination when building the loft/open area plan.
If I am understanding your question right... I'd use use the trusses over the loft. But over the cathedral ceiling you don't have floor joists to hold the walls together. So go with rafter ties at the top of the wall over that area.
Not sure which 20x30 you are referencing. Could yo post that?
Question: where is the build going to be? If you are in a code area it would be useful to know what code they are using. In any event you could mix trusses at one end and then rafters with rafter ties at the other.