House space for a light bird with big habits
Allow roughly three to four square feet of house space per Leghorn, and at least eight to ten square feet of outdoor run per bird as a working minimum. Those numbers come with a breed warning attached: Leghorns are the athletes of the laying world, lean, quick, and perpetually busy, and they experience crowding sooner than a placid heavy breed does. A flock of Leghorns in a pen that would content a group of Orpingtons will advertise its frustration in pulled feathers, flighty panic at every shadow, and hens laying anywhere except the nest boxes.
Roosting space is the dimension keepers forget. Chickens sleep on perches, and a Leghorn flock needs enough linear roost, roughly a generous handspan per bird and more in hot weather, arranged so the lowest birds are not forced onto the floor under the droppings of the highest. Nest boxes follow a similar social rule: several hens will always favour the same box, but too few boxes for the flock produces floor eggs, broken eggs, and egg eating, which is why a box for every few hens, filled with clean, inviting litter, is part of the space budget rather than a furnishing detail.
The run an active layer actually uses
A Leghorn run should be designed for occupation. Bare earth bores this breed, and a bored Leghorn invents entertainment at her flockmates' expense, so the run earns its keep with scratching material to work through, dust-bathing spots in dry soil or sand, perches and stumps at varied heights, and feed scattered or hung so that finding it takes time. Free range suits Leghorns beautifully where it is safe, since they forage widely and efficiently, but their foraging range is also a statement about fencing, because a bird this light flies over ordinary fences without apparent effort.
That flightiness drives the security design in two directions. The run needs height or a netted roof to keep Leghorns in, and the house needs to be a fortress at night to keep predators out, because a Leghorn asleep is as defenceless as any chicken and the breed's daytime alertness buys it nothing after dark. Mesh fine enough to exclude small predators, a solid floor or buried skirt against digging, and door fastenings that a raccoon's hands cannot worry open are the provisions that decide whether the flock gets to use its space for years.
Feeding and watering space in a competitive flock
Leghorns eat socially and competitively, and a single small feeder in a big run creates a daily contest the timid birds lose. Spread feeding and watering points so several birds can use them at once and the lowest-ranking hen can eat at a second station in peace, and place drinkers where the flock passes often, because layers in full production drink heavily and a hen that shortens her water intake shortens her laying within days. Grit and shell need their own little stations too, available constantly rather than offered occasionally.
In winter, when the run is mud and the flock spends more hours indoors, the house figures tighten in practice: a flock that was content in summer can feud in February if its indoor space has no spare corner to retreat into. Planning the house for the winter population, not the summer one, is the honest way to size it.
Space now, records for the flock's future
A Leghorn flock kept across its full lifespan becomes a layered population of pullets, layers, and retired hens, and its space and feeding arrangements evolve with it. Keeping simple per-bird records of laying, health, and temperament turns that evolution into management instead of muddle. Should the flock pass to another keeper, KinsLe's Transferrable Profiles let each bird's profile move with it, so laying patterns and health notes inform the new flock's care from the first morning.