Good to Occupy one privy in packed house (5)
I believe the answer is:
igloo
'packed house' is the definition.
(I've seen this before)
'good to occupy one privy' is the wordplay.
'good' becomes 'g' (abbreviation).
'to occupy' means one lot of letters goes inside another (I've seen this in other clues).
'one' becomes 'i' (Roman numeral).
'privy' becomes 'loo' (loo is a kind of privy).
'i'+'loo'='iloo'
'g' inserted within 'iloo' is 'IGLOO'.
'in' acts as a link.
(Other definitions for igloo that I've seen before include "home in the cold" , "Greenland dwelling" , "Icy home for Eskimo" , "An eskimo's ice-house" , "From domed hut" .)