Old house often mocked in the suburbs (5)
I believe the answer is:
tudor
I believe this is a double definition.
'old house' is the first definition.
(historical royal house)
'often mocked in the suburbs' is the second definition.
(as in mock Tudor houses)
(Other definitions for tudor that I've seen before include "Elizabeth I, perhaps" , "Rose" , "Style of architecture in 15th c. England" , "Royal family, fourteen eighty five to sixteen hundred and three" , "regal dynasty" .)