What is the sale-able area of a condominium

Saleable area in a condominium is not the exact use-able apartment floor area, as sale-able area is measured from the center of the walls of the condominium which are not common property (Chapter II of the Condominium Act). The outside walls of a condominium building is common ownership of the condominium, walls between adjoining units are private ownership. For example the air-conditioning unit attached permanently to the outside wall of a condominium in common property.