Establish a building (9)
I believe the answer is:
institute
I believe this clue is a double definition.
'establish' is the first definition.
(I know that establish can be written as institute)
'a building' is the second definition.
(I know that institute is a type of building)
(Other definitions for institute that I've seen before include "Establish - seat of learning" , "Found; an establishment" , "order as before" , "Begin (legal proceedings)" , "asylum, possibly?" .)