Designer, cold, is seen in her attic unexpectedly (9)
I believe the answer is:
architect
'designer' is the definition.
(I know that designer can be written as architect)
'cold is seen in her attic unexpectedly' is the wordplay.
'cold' becomes 'c' (abbreviation, eg on taps).
'is seen in' is an insertion indicator.
'unexpectedly' indicates anagramming the letters.
'her'+'attic'='herattic'
'herattic' is an anagram of 'arhitect'.
'c' going into 'arhitect' is 'ARCHITECT'.
(Other definitions for architect that I've seen before include "Building designer" , "professional" , "Perhaps Scott" , "Designer of buildings" , "Author" .)