An idealized four-storey stone building with reinforced concrete and wooden floors is analyzed. Five models involving different combinations of rigid and flexible floors have been studied, and their influence on the dynamic response of the building is established. Linear dynamic analyses have been carried out. As established, no combination of wooden and reinforced concrete floors substantially improves response, and the properties of the building with mixed floors, elevation-wise, resemble those of a building having only wooden floors. This raises doubts as to the efficiency of partial floor strengthening to which the design engineer often has to resort in dealing with stone buildings - cultural monuments.