Chalet collapsing around one is good (7)
I believe the answer is:
ethical
'is good' is the definition.
(thesaurus)
'chalet collapsing around one' is the wordplay.
'collapsing' indicates an anagram.
'around' means one lot of letters goes inside another.
'one' becomes 'i' (Roman numeral).
'chalet' anagrammed gives 'ethcal'.
'ethcal' going around 'i' is 'ETHICAL'.
(Other definitions for ethical that I've seen before include "Abiding by moral principles" , "In accordance with approved moral standards" , "Relating to morals" , "Morally correct, in accordance with professional standards" , "Conforming to accepted standards of behaviour" .)