Part of prefab beyond religious building (5)

I believe the answer is:
abbey
'religious building' is the definition.
(I've seen this before)
'part of prefab beyond' is the wordplay.
'part of' indicates a hidden word.
'ABBEY' is hidden within 'prefab beyond'.
(Other definitions for abbey that I've seen before include "Church (once linked to convent or priory)" , "Monastery" , "eg Bath, Fountains" , "Religious building" , "Monks'/nuns' building" .)