Also read definition of 'factory' under Section 2 (e) of the Central Excise Act, 1944
SECTION 2 DEFINITIONS
(e) “factory” means any premises, including the precincts thereof, wherein or in any part of which excisable goods other than salt are manufactured, or wherein or in any part of which any manufacturing process connected with the production of these goods is being carried on or is ordinarily carried on;
Without installation of machinery in connection with the any manufacturing process, the empty premises/building cannot be called 'factory'
Machinery is an integral part of factory. Without machinery it is called building. There are also so many other parameters/factors to be qualified to term any building a factory..