(1) In this Act "office" means any room of a building of which the substantial use is for clerical work including book-keeping, filing, typing, duplicating, machine calculating, drawing, the editorial preparation of matter for publication in print, the sorting and carrying of papers, telephone operating, and the handling of money, except any rooms in premises of which the substantial use is private residence or for private domestic purposes.

(2) In this Act, "office" also includes establishments, institutions and administrative services in which the workers are mainly engaged in office work.