I am trying to get my head around the best way to line the house in the far, far, future when it eventually goes up.  The wall structure, from the outside in, will be rainscreen (timber/render), batten, Proctor Wraptite, OSB (or something more breathable tbc), 300mm I-beam with warmcell, OSB, (?vcl), batten/service void, plasterboard or Fermacell. We will probably go for either a shadow gap to the floor or flush skirting/ architrave with a shadow gap to the walls.  As far as I can see