Hothouse Roy altered to accommodate cooker (8)
I believe the answer is:
orangery
'hothouse' is the definition.
(thesaurus)
'roy altered to accommodate cooker' is the wordplay.
'altered' is an anagram indicator.
'to accommodate' indicates putting letters inside.
'cooker' becomes 'range' (I've seen this before).
'roy' is an anagram of 'ory'.
'ory' going around 'range' is 'ORANGERY'.
(Other definitions for orangery that I've seen before include "Conservatory for growing citrus plants" , "Citrus hothouse" , "Type of conservatory" , "Greenhouse for fruit bushes" , "Building for citrus growing" .)