Most magnificent garden redesigned, facing street (8)
I believe the answer is:
grandest
'most magnificent' is the definition.
'garden redesigned facing street' is the wordplay.
'redesigned' is an anagram indicator.
'facing' means one lot of letters go next to another.
'street' becomes 'st'.
'garden' is an anagram of 'grande'.
'grande'+'st'='GRANDEST'
(Other definitions for grandest that I've seen before include "Most majestic" , "Most august" .)