Source : Webster's Revised Unabridged Dictionary (1913)

Roominess \Room"i*ness\, n.
   The quality or state of being roomy; spaciousness; as, the
   roominess of a hall.

Source : WordNet®

roominess
     n : spatial largeness (especially inside a building) [syn: {capaciousness},
          {spaciousness}, {commodiousness}]