This takes the FIII to the extreme by eliminating the split levels and the access corridor and, in doing so, becomes a variant of Moisei Ginzburg's Type E apartment building that has staircases accessing all floors and not just three. Private spaces are on both sides of the staircase but ever third floor on one side remains shared living space. 

 

Elevators and fire-escape stairs are at the ends of the building. The living room runs full-length and functions as a sidewalk-like horizontal circulation space. The stairs permit diagonal circulation but the mode of that circulation is arbitrary as there is more than one way home. There is thus no compulsion for anyone to use any particular living area. 

 

Despite there being two doors between shared spaces and private spaces, living at such a density will required everyone to have a strong and shared sense of common purpose.