Full length of the former accommodation (6)
I believe the answer is:
extent
'full length' is the definition.
'extent' can be an answer for 'length' (I've seen this before). I am not certain of the 'full' bit.
'former accommodation' is the wordplay.
'former' becomes 'ex' (prefix meaning former or onetime).
'accommodation' becomes 'tent' (I have seen 'Temporary accommodation' mean 'tent' so perhaps 'accommodation' could also mean 'tent').
'ex'+'tent'='EXTENT'
'of the' acts as a link.
Can you help me to learn more?
(Other definitions for extent that I've seen before include "Compass, scope" , "The size or scale of something" , "Bulk - compass" , "Measure" , "Scope, area" .)