Section 16(4)(d) in The Merchant Shipping (Crew Accommodation) Rules, 1960
(d)In determining floor area of a room for the purpose of this sub-rule, spaces occupied by berths, lockers, seats or chests of drawers shall be taken into account but any spaces which by reasons of their small size or irregular shape cannot accommodate furniture and do not contribute to the area available for free movement shall not be taken into account.