A dry, freezing cold, unfinished loft (5)
I believe the answer is:
attic
'loft' is the definition.
('attic' can be a synonym of 'loft')
'a dry freezing cold unfinished' is the wordplay.
'dry' becomes 'tt' (abbreviation for teetotal).
'freezing cold' becomes 'icy' (I've seen this before).
'unfinished' means to remove the last letter.
'icy' with its last letter taken away is 'ic'.
'a'+'tt'+'ic'='ATTIC'
(Other definitions for attic that I've seen before include "Floor" , "Room inside a building's roof space" , "Area at the top of the house" , "Dusty room" , "of Greek region" .)