Roger, on the upper level braces you mention, can the braces be used on the lower side in order to keep the transom area more open for windows? I would like to allow as much natural light into that area as possible. Basically, put the braces running from the beam that runs from the midpoint of the ties up to the secondary posts on to of the ties (rather than from those posts to the plates)?
If it isn't clear what I mean by that, I can update the model and post updated pictures.
All of your other recommendations make sense and I will implement those.
Any value to offsetting the secondary posts and the beams between the midpoints of the ties? I suspect with the mortises offset, it can only be better for the strength of the ties. I would probably leave the secondary posts where they are and either make the loft deeper or shallower.
Paul, the inspiration came somewhat from the Appalachian Trail Shelter. With my smaller footprint, the loft couldn't be offset quite so much. The advantage to their larger footprint was that the secondary post came down off-center on the tie and was near the brace.
