Poultry and livestock buildings

A building designed around the animals

Poultry houses, pig barns, dairy and beef barns are production buildings where the indoor climate directly affects animal health, growth and output. The structure must deliver controlled ventilation, thermal comfort, daylight or light control, cleanability and biosecurity, and it must survive an aggressive environment of ammonia, humidity, dust and washdown. Pre-engineered steel provides long clear spans without internal posts – easier for feeding lines, manure removal and cleaning – and repeatable kits for integrators who build many houses on one farm. This article focuses on the livestock-specific requirements; general farm buildings are covered in agricultural buildings.

Ventilation and climate control

Tunnel ventilation – banks of exhaust fans in one end wall pull air the full length of the house, entering through evaporative cooling pads at the other end – is the standard for broilers in hot climates. The building must be airtight to work, so cladding laps, eaves and doors are sealed, and the roof is insulated or fitted with a ceiling to reduce heat gain. In milder climates, curtain-sided houses use winch-operated side curtains with ridge or eave inlets for minimum ventilation. Dairy barns rely on natural ventilation through open sidewalls and an open ridge or roof monitor; a common rule of thumb is an open ridge width of roughly 50 mm for every 3 m of building width, with roof slopes around 14–18° to drive the stack effect.

Loads specific to livestock buildings

• Suspended equipment – feed lines, drinker lines, heaters, lights, fans and cooling pads hang from the roof framing, often on winches that can be raised for cleaning. These loads are significant and concentrated and must be given to the designer as collateral and point loads.
• End-wall fan loads – large tunnel fans and pads need framed openings in the end walls; the open area changes internal wind pressure.
• Ceiling and insulation – insulated ceilings or sandwich panels add dead load and govern purlin layout.
• Risk category – low human occupancy may allow reduced design loads (for example Risk Category I in ASCE 7-22 or Importance Level 1 in AS/NZS 1170.0) where accepted by the authority; NBC 2020 includes specific provisions for farm buildings.

Corrosion, hygiene and biosecurity

Ammonia, moisture and washdown chemicals make livestock houses one of the harshest environments for steel, often equivalent to ISO 12944-2 category C4–C5 inside. Recommended measures are hot-dip galvanized primary and secondary framing or a duplex system (see surface preparation and painting), high-durability coated or stainless fasteners, roof and wall sheeting with heavier metallic coating and a liner or sandwich panel with an easily cleaned inner face. Details should avoid ledges and pockets that trap manure and dust; base connections are best raised on concrete upstands above the wash-down floor. Bird-proof closures and screens keep wild birds out, an important biosecurity measure against avian disease.

World Steel livestock buildings

World Steel supplies poultry houses, pig barns and dairy structures as galvanized PEB buildings with framed fan and pad openings, insulated cladding and accessories, packed as repeatable kits for multi-house farms. See the agriculture industry page for related projects and services.