My current home was originally build with a loft and I wish to extend the loft completely across making a second floor - and create two new bedrooms, and a full bath. The loft floor is framed with 2x6s to an existing double 2x12 beam. I will basically be removing the entire loft, and reframing the entire floor system.
The span is a simple span ~18+/- and I have sized the joists for the span and deflection. I was planning on using either open joists (to ease running HVAC) or using wood i-beams. What is the best way to connect to the existing outside wall structure? Is is better to simply hang the i-beams to the top plate with hangers (keeping i-beams in line with the studs)? Or even go as far as a ledger board with hangers? The exterior walls are 2x6 framing.