The purpose of annexation is based on the case of Leigh v Taylor , D'Eyncourt v Gregory  and Dean v Andrew 
In the case of D'Eyncourt v Gregory , the chattel will become a fixture if the purpose of annexation is to improve the property itself.
In the case, of Leigh v Taylor  , the chattel will remain as a chattel, if the purpose of annexation is so that the chattel could be enjoyed as a chattel.
In the case of Dean v Andrew , the objective consideration is proposed in identifying the purpose of annexation. The subjective consideration may be persuasive.
In general, the purpose of annexation will determine either the structure is a fixture or not ?