Built up resort remodelled - it will cause difficulty (4,2,7)

'built' is the definition.
I don't know anything about this answer so I can't judge whether it can be defined by this definition.

'up resort remodelled it will cause difficulty' is the wordplay.
I cannot quite see how this works, but
'up' is found in the answer.
'it' could be 't' (abbreviation. e.g. in 'tis) and 't' is found within the answer.
'cause' could be 'sir' (Sir is an example) and 'sir' is present in the remaining letters.
'difficulty' could be 'trouble' (trouble can mean a difficult situation) and 'trouble' is found within the answer.
This accounts for all the letters.
This may be the basis of the clue (or it may be nonsense).

Can you help me to learn more?