Ready-made house (6)
I believe the answer is:
prefab
'ready-made house' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for prefab that I've seen before include "Cheap building" , "Building assembled from pre-manufactured parts, in short" , "Building assembled with sections made elsewhere" , "small postwar house" , "British inter-war temporary housing, popularly called" .)