After end of business, building is closed (4)
I believe the answer is:
shut
'is closed' is the definition.
('shut' is associated in meaning with 'closed')
'after end of business building' is the wordplay.
'after' means one lot of letters go next to another.
'end of' suggests the final letters.
'building' becomes 'hut' (I've seen this before**).
The last letter of 'business' is 's'.
's' put next to 'hut' is 'SHUT'.
(Other definitions for shut that I've seen before include "Out of business" , "Closed" , "Close" , "Slam" , "See 19" .)