Architect and town planner set up two hospitals (4)
I believe the answer is:
nash
'architect and town planner' is the definition.
(John Nash)
'set up two hospitals' is the wordplay.
'two hospitals' can mean two replacements for 'hospital'.
'set up' is a reversal indicator.
'hospital' becomes 'san' (I've seen this in other clues).
'hospital' becomes 'h'.
'san' in reverse letter order is 'nas'.
'nas'+'h'='NASH'
(Other definitions for nash that I've seen before include "Famed English architect" , "Ogden --, author" , "English architect, d. 1835 - American poet, d. 1971" , "Ogden --, US humorous poet" , "John --, British architect" .)