Principle is to accommodate blokes in housing (8)
I believe the answer is:
tenement
'housing' is the definition.
(I have seen 'Undesirable housing' mean 'tenement' so perhaps 'housing' could also mean 'tenement')
'principle is to accommodate blokes' is the wordplay.
'principle' becomes 'tenet' (a tenet is a principle or value).
'is to accommodate' means one lot of letters goes inside another.
'blokes' becomes 'men' (bloke can informally mean a man).
'tenet' enclosing 'men' is 'TENEMENT'.
'in' is the link.
(Other definitions for tenement that I've seen before include "Flat" , "Run-down dwelling housing many people" , "Building divided into small let units" , "Old dwelling for multiple occupation" , "Rundown house with many occupants" .)