House evacuated, surrounded by top command (6)
I believe the answer is:
behest
'command' is the definition.
(behest is a kind of command)
'house evacuated surrounded by top' is the wordplay.
'evacuated' suggests removing the centre.
'surrounded by' means one lot of letters goes inside another.
'top' becomes 'best' ('best' can be similar in meaning to 'top'**).
'house' with its centre taken out is 'he'.
'he' going within 'best' is 'BEHEST'.
(Other definitions for behest that I've seen before include "Command, bidding" , "(At someone's) command" , "Command - Thebes (anag)" , "Order" .)