34. The housing system may be aviary, perchery or deep litter, as described earlier, with the essential addition that the birds must be provided with continuous daytime access to land mainly covered with vegetation. Sleeping, nesting, feeding and watering are generally within the building; litter is provided either inside or, increasingly, under a covered area outside. Outside shelter and shade are also recommended. Access to the outside is generally via popholes; these have greatly increased in size in recent years in order to encourage greater numbers of birds to venture out. This means that the houses are colder during the day time in winter.
35. Stocking density within the building depends on the housing system. Stocking density on the associated land area must not exceed 1,000 birds/ha for the eggs to be described as free range under the current EC Egg Marketing Regulations. Up to 4,000 birds/ha is allowable if the eggs are described as "semi-intensive". As far as is known there are none of these "semi-intensive" units in the UK but eggs may be imported from other countries where this system is widely in use.