12. Laying hens must have—
(a)at least 750cm2 of cage area per hen, 600cm2 of which shall be usable area; the height of the cage other than that above the usable area shall be at least 20cm at every point and no cage shall have a total area that is less than 2000cm2;
(b)a nest;
(c)litter such that pecking and scratching are possible; and
(d)appropriate perches allowing at least 15cm per hen.