Can still be converted into private quarters (7)
I believe the answer is:
billets
'quarters' is the definition.
('billet' can be a synonym of 'quarter')
'can still be' is the wordplay.
'can' is an anagram indicator (I've seen 'canned' mean this (canned can mean drunk)).
'still'+'be'='stillbe'
'stillbe' is an anagram of 'BILLETS'.
'converted into private' is the link.
This may not be right. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for billets that I've seen before include "Soldiers' lodgings" , "Lodgings for the military" .)