Was it put on by queen to house old flame? (6)
I believe the answer is:
annexe
'was it put on' is the definition.
(annexe can mean an extension put onto a house)
'queen to house old flame?' is the wordplay.
'queen' becomes 'anne' (I've seen this before).
'to house' is an insertion indicator.
'old flame?' becomes 'ex' (I've seen this in other clues).
'anne' placed around 'ex' is 'ANNEXE'.
'by' acts as a link.
(Other definitions for annexe that I've seen before include "Appropriate into one's territory" , "Building attached to a largerone" , "Supplementary part" , "Addendum" , "Additional building" .)