The HKI Association is committed to ensuring that both solid fuel fireplaces and home ventilation systems in buildings can be operated together. In a group of experts with the trades involved, the status of the legal basis and the knowledge of the trades for the use of a solid fuel fireplace and a ventilation system in a building or a usage unit were compiled in an overview and the responsibilities were presented. Model declarations (manufacturer's declaration for home ventilation units and specialist entrepreneur's declaration) are also provided to facilitate their application in practice. Through its activities and cooperation with the trades, the HKI supports its members for the success of the joint operation in the practical implementation.