Area of old temporary accommodation (6)
I believe the answer is:
extent
'area' is the definition.
(I've seen this before)
'old temporary accommodation' is the wordplay.
'old' becomes 'ex' (prefix meaning former or onetime).
'temporary accommodation' becomes 'tent' (I've seen this before).
'ex'+'tent'='EXTENT'
'of' is the link.
(Other definitions for extent that I've seen before include "reach?" , "Compass, scope" , "A cake; last word of Macbeth" , "Measure" , "Magnitude - scope" .)