Good insulation of the building helps keep the hen house warm. In cold weather, the poultry house should be heated in order to guarantee steady production. The heating of the hen house can be arranged by using aluminum heating elements that are fast and easy to install on the wall. Heating costs can be reduced by recovering the heat generated in the poultry housing system. The air is circulated through a special heat recovery ventilation system that filters the air and introduces it back to the hen house together with fresh air from outside.