Without dividing walls (4-4)
I believe the answer is:
open-plan
'without dividing walls' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for open-plan that I've seen before include "style in office" , "Offices without walls" , "No pen pal in office lay-out without partitions" , "(Of office) having few dividing walls" , "Office without walls" .)