A Stubbed Attic Truss is very similar in properties to the Attic Truss but the ends at the supports are heightened so the height of the soffit is usually above the bottom of the bottom chord. This can achieve more height inside of the room where span is limited and pitch isn’t very steep.
The Space Attic (or Posi-Attic) is the same as a Stubbed Attic Truss, but the solid timber member used for the floor section (the bottom chord) is replaced with the ITW Metal Web Joist system. The overall depth of the “bottom chord” will be more than the traditional 222mm. It could be as deep as 354mm. This allows space in a zone to run your cables through for electricity, plumbing, MVHR and home cinemas. With a traditional Attic and Stubbed Attic, they have to be run in the areas outside of the room. You must not drill holes or notches to run these cables/pipes, so the Space Attic may be a better solution depending on your design preferences for the room.