Without thinking, building home next to an East Anglian city (7)
I believe the answer is:
'without thinking' is the definition.
'home next to an east anglian city' is the wordplay.
'home' becomes 'in' ('he's home' can mean 'he's in').
'next to' says to put letters next to each other.
'east anglian city' becomes 'ely' (I've seen this before).
'building' is the link.
(Other definitions for inanely that I've seen before include "in a daft way", "How fools behave", "Vapidly", "Stupidly", "Senselessly".)