The building is thought to have originated as a stable block and service wing for the adjacent Mostyn House, the C18 town house of the Mostyn family.
Credir mai stablau oedd yr adeilad yn wreiddiol ynghyd ag adain wasanaethu ar gyfer Tŷ Mostyn sydd wrth ei ymyl, sef tŷ tref y teulu Mostyn yn y 18fed ganrif.