In this paper, a 6 storey existing RC building is investigated in terms of having different joint types between the masonry infills and RC frame. First, the building is modelled according to the pre-described project of its own. Then, dynamic characteristics of the structure are found for the bare frame, since it is the most common type of designing technique being used currently. Following that, different connection approaches are implemented along the infill-frame interfaces of the building elements. In order to understand influence of the joints on the building dynamic characteristics, two extreme conditions are taken into consideration, namely stiff and hinged connections. Furthermore, an innovative solution using flexible polyurethanes (polymer PM) as a joint element between RC frame and masonry infill is proposed. This new method exhibits a highly ductile behaviour and therefore it increases the modal periods of the building, compared to the stiff one. On the other hand, due to the intrinsic features of the material such as visco-elastic behaviour that leads to dissipate energy, a visible contribution to the building damping parameters is also observed in time history analysis. Finally, three different connection options are compared between each other and the results are discussed. Large deformability capacity with highly durable reaction ability against the external forces is one of the most crucial points from structural engineering perspective. According to the results of this study, the new proposed method gives promising expectations that such approach might be used in seismic areas both for existing buildings and new constructions. In addition, dynamic behaviours of the building with different joint types also revealed the importance of masonry modelling whilst designing as well as choosing an appropriate connection method.