To put it briefly, the shape the homes are in (8)
I believe the answer is:
condense
'to put it briefly the' is the definition.
I can't judge whether this defines the answer.
'shape the homes are in' is the wordplay.
'shape' becomes 'cone' (cone is a kind of shape).
'the homes are' becomes 'dens' (I can't explain this - if you can you should give a lot more credence to this answer).
'in' is an insertion indicator.
'cone' placed around 'dens' is 'CONDENSE'.
Can you help me to learn more?
(Other definitions for condense that I've seen before include "Abridge" , "Turn from gas to liquid" , "Summarise" , "Concentrate" , "Send once (anag.)" .)