Rickety shelter housing one in island capital (2,6)
I believe the answer is:
st helier
'island capital' is the definition.
(capital of Jersey)
'rickety shelter housing one' is the wordplay.
'rickety' indicates an anagram.
'housing' indicates putting letters inside.
'one' becomes 'i' (Roman numeral).
'shelter' with letters rearranged gives 'stheler'.
'stheler' going around 'i' is 'ST HELIER'.
'in' acts as a link.
(Other definitions for st helier that I've seen before include "Island capital" , "Jersey's capital" , "Capital of Jersey" , "island town" .)