basementmeans a floor (however described) immediately below the ground floor;
factory premisesmeans premises constituting, or forming part of, a factory within the meaning of the Factories Act 1961 and premises to which sections 123(1) and 124 of that Act (application to electrical stations and institutions) apply;
first floormeans the floor above the ground floor;
the 1971 Actmeans the Fire Precautions Act 1971;