On the great room end wall of the main structure is it ok to replace the door and window as drawn with a sliding glass door?
There is a long span beam load coming down the center of that wall. Note the heavy header over the window in the Loft Plan. You could do an appropriate header over a sliding door at the lower level as well. The size should be checked locally for your snow load. It might be a triple 2x12 or an LVL.
I will not be using a ridge beam for the roof, collar ties and gussets. Does this make any difference?
What is the plan for the roof?
If you are doing the Alternative Cross Section for the simple studio house layout then the roof load will be off the end wall. A double 2x8 would be fine for the slider header.
Check that the diagrammed roof framing will work in your location and consider a truss company design if you are in a code area. They will factor in all the wind and snow loads.
I am using the alternative cross section roof design. I will run this by my building inspector first and probably upgrade to 2X10 rafters. Thanks for the information. I was thinking this would be OK since the load is on the side walls with this design. As always, Great site and quick replies!!! [cool]