Room or space under a roof (4)
I believe the answer is:
loft
I believe this is a double definition.
'room' is the first definition.
(I've seen this before)
'space under a roof' is the second definition.
(I've seen this before)
(Other definitions for loft that I've seen before include "Roof space area" , "Send ball in a high arc - in a barn?" , "Raised shelter for pigeons" , "Backward slope in face of golf club" , "Place for keeping racing pigeons" .)