Basic accommodation's one good toilet? (5)
I believe the answer is:
igloo
'basic accommodation's' is the definition.
'igloo' can be an answer for 'accommodation's' (I have seen 'cold accommodation' mean 'igloo' so perhaps 'accommodation' could also mean 'igloo'). I am not sure about the 'basic' bit.
'one good toilet?' is the wordplay.
'one' becomes 'i' (Roman numeral).
'good' becomes 'g' (abbreviation).
'toilet?' becomes 'loo' (loo can informally mean a toilet).
'i'+'g'+'loo'='IGLOO'
Can you help me to learn more?
(Other definitions for igloo that I've seen before include "Arctic dwelling" , "Stacked blocks" , "basic dwelling" , "Inuit building" , "native dwelling" .)