Hi, I am planning on converting our bungalow into a 2 storey house and would like to do it out of timber panels I will construct on site. So my concern is the cavity and thermal bridging. My original plan was to fix a ring beam around the inner leaf, strap it down, fix my floor joists to it then build the new walls off the floor joists. However iam realising I can't breach the cavity with the joists. So can i close the cavity with an insulated cavity fire sock, dpm on top then my ring beam plate 225mm over the 2 walls, then I can build the new walls in line with the external walls, and the joists can sit on the inner leaf?? Has anyone else done this? Any suggestions?? Cheers