During the earthquake occurred in Emilia Romagna (northern Italy) in 2012, many issues related to connections systems in industrial precast buildings have been underlined. In the paper the influence of roof systems in the seismic response of one-storey precast structures is analyzed for two case studies. In particular the influence of roof elements to beams connections on the global behaviour of precast structures is deepen. The global behaviour of the structure is in fact strongly influenced by the disposition of connections. The disposition of the roof elements to beam connections generates different static schemes (isostatic or hyperstatic) of the elements themselves. Hence the connections disposition influences the forces distribution on the other structural elements, such as beams and columns.

Furthermore the influence of connections stiffness has been investigated in the paper. The stiffness has been considered in the analyses both with infinite value and with its real value.

The connections can be designed in order to fail in a ductile way and to prevent brittle failure. It has been shown that the real stiffness of connections and the static scheme of the roof system can strongly influence the connections design.

The importance of global analyses of the structure, that aim to evaluate a priority list of adequate interventions in order to optimize the seismic performance of the structure itself and to reduce the intervention cost, is stressed in the paper.