Important factors to consider in designing your cage-free housing are as follows:

The provision of sufficient space to live – the maximum density permitted in the EU for barn and free-range systems is 9 birds/m2, but reducing this to 7 birds/m2 can significantly benefit the hens – giving them more space to move freely. We recommend a maximum stocking density of 15 birds/m2 at the floor level in an aviary barn system.
Providing sufficient enrichment materials to occupy the hens such as foraging, pecking and dustbathing substrates, and plenty of perching space.
Providing different functional spaces – e.g. separate day and night quarters, with high perches for resting, plenty of nest boxes, and separate activity zones for dustbathing, foraging and scratching; or at least access to a veranda and natural light.
Free range systems should have good shade and shelter to encourage outdoor ranging, and a variety of herbs, shrubs, and grasses to satisfy the foraging needs of the hens.
It is also important that the pullet rearing house is similar in design to the laying house as this allows the young hens to get accustomed to perching – especially jumping on and off the perches - so they don’t injure themselves. They will also be less fearful of their new surroundings when moved into a similar style of laying house.
Future proofing your business – investment is critical to commercial sustainability and will allow you to prepare for upcoming issues such as the need to operate without beak trimming, improving keel bone damage and maintaining good feather coverage, as well as providing more natural light, giving the birds access to verandas and addressing the need to end the unnecessary killing of male chicks.

View our latest resources on housing design here:

Practical Guide - Alternative cage-free systems for laying hens
Summary - Additional guidance on multi-tier systems
Video - Fit for purpose cage free system for laying hens
Video - Noble Foods - making cage free eggs a commercial reality
Case study - The importance of appropriate pullet rearing