Balcony largely in need of repair (7)
I believe the answer is:
gallery
'balcony' is the definition.
(gallery is a kind of balcony)
'largely in need of repair' is the wordplay.
'in need of repair' is an anagram indicator.
'largely' is an anagram of 'GALLERY'.
(Other definitions for gallery that I've seen before include "Place where pictures are exhibited" , "Group of spectators" , "Theatre area" , "Horizontal mine passage" , "Building for works of art" .)