House and run figures for a duck that never sits still
Plan on roughly four square feet of house space per Khaki Campbell duck, and at least ten to fifteen square feet of outdoor run per bird, with more run genuinely better. The Campbell is a light, upright, energetic duck, bred from laying stock with Indian Runner ancestry, and it treats its territory as a workplace: foraging, dabbling, patrolling, and bathing from dawn to dusk. Ducks are also ground-level birds that sleep on the floor rather than perching, so house space is floor space, measured honestly after feeders and drinkers take their share, and bedding depth is part of the calculation, because a duck house stays healthy only when the litter is deep, dry, and regularly topped up.
Height can be modest. A low, well-ventilated house that a keeper can clean without crawling is ideal, and ventilation matters more than insulation for hardy ducks, provided the sleeping area is draught-free at bird level and the whole building is secure. Ducks tolerate cold far better than they tolerate damp and ammonia, so a house that breathes at the top and stays dry at the bottom suits Campbells in most climates.
The water corner, and the mud it manufactures
Water defines duck space planning. A Campbell needs water deep enough to submerge her head completely, to keep her eyes and nostrils clean and healthy, and she will splash enthusiastically in anything provided. That corner of the run turns to soup within days if the trough or pool sits on soil, fouling the area and giving the flock a permanent wet patch to carry bacteria around on their feet. The practical answer is hard standing: slabs, decking, or a gravel bed under and around the water, sloped so splashes drain away from the house, with the water itself refreshed often enough to stay inviting rather than stagnant.
A swimming pond is a pleasure for ducks but not a requirement, and a small, filthy pond is worse than a clean, modest trough. If a pond is part of the plan, size the run to include banks the ducks will not instantly erode, and accept that the water area, not the grass, is where this flock will spend its happiest and messiest hours.
Security: the space rule that overrides all others
Every dimension is academic if the enclosure is not predator-proof, because ducks are defenceless at night and Campbells, being light birds, have no bulk to protect them. The house needs solid walls or small-gauge mesh, a floor or a skirt that defeats digging, and a door that latches against clever paws, and the run needs a covered top or a reliably locked-away flock at dusk. Plan the layout so the evening routine, herding ducks in and shutting the door, is easy in the dark and rain, because the routine that is easy is the routine that happens every night.
Campbells can fly a little when startled, especially young, lighter birds, so run fencing should have some height or a netted top in open country.
Rotation, forage, and the working run
Given grass, Campbells repay it by harvesting slugs, insects, and weeds, which makes them valued orchard and garden ducks, but a static run is grazed and trampled to mud in short order. Two runs used alternately, or a movable house and fence that shift the flock onto fresh ground, keeps forage in the system and gives the rested ground time to recover and dry. In winter, when every duck run tends toward the swamp, extra area on the driest ground you have, plus hard standing by the house and water, carries the flock through without foot trouble.
A laying flock kept for years keeps records worth having: which hens lay through winter, which drake is fertile, which bird had the sore foot. KinsLe's Transferrable Profiles let those profiles pass with the ducks if the flock changes keeper, so laying records and health notes arrive in the new run with them.