More spacious area that is altogether final (7)
I believe the answer is:
roomier
'more spacious' is the definition.
('roomy' can be a synonym of 'spacious')
'area that is altogether final' is the wordplay.
'area' becomes 'room' (room is a kind of area**).
'that is' becomes 'ie' ('i.e.' can be a synonym of 'that is').
'final' indicates one should take the final letters.
The last letter of 'altogether' is 'r'.
'room'+'ie'+'r'='ROOMIER'
(Other definitions for roomier that I've seen before include "less cramped" , "More spacious" .)