Loos redesigned for European capital (4)
I believe the answer is:
oslo
'european capital' is the definition.
(I've seen this before)
'loos redesigned' is the wordplay.
'redesigned' indicates an anagram.
'loos' with letters rearranged gives 'OSLO'.
'for' is the link.
(Other definitions for oslo that I've seen before include "Location" , "Northern city" , "where Ibsen lived under another name" , "Norwegian capital" , "Former Christiania" .)