Farm building, old, like the ones accommodating half of us (9)

'farm building' is the definition.
'oasthouse' can be an answer for 'building' (oasthouse is a type of building). I'm not sure about the 'farm' bit.

'old like the ones accommodating half of us' is the wordplay.
'old' becomes 'o' (abbreviation).
'like' becomes 'as'.
'the ones' becomes 'those' (I can't justify this - if you can you should give a lot more credence to this answer).
'accommodating' indicates putting letters inside.
'half of' indicates taking half.
'us' cut in half is 'u'.
'those' placed around 'u' is 'thouse'.
'o'+'as'+'thouse'='OASTHOUSE'

Can you help me to learn more?