(1) Except as provided in Sentence (3), a window or access panel providing an opening not less than 1 100 mm high and 550 mm wide and having a sill height of not more than 900 mm above the floor shall be provided on the second and third storeys of every building in at least one wall facing on a street if such storeys are not sprinklered.
(2) Access panels required in Sentence (1) shall be readily openable from both inside and outside or be glazed with plain glass.
(3) Access panels required in Sentence (1) need not be provided in houses.