The paper presents a simple methodology for estimation of the response modification factor (R-Factor) in Puzzle Building Frame (PBF). Meanwhile, brief introduction about the mentioned system (PBF) is presented. R-Factor is one of the seismic design parameters that has a great impact on the reduction of applied base shear forces during powerful earthquakes. The base shear, which is determined by the elastic strength demand that divided by a seismic force modification factor R, is the general method in seismic design codes. This factor reflects the influence of the elastic–plastic deformation and energy-dissipating capacity on the seismic force. Precise determination of response modification factor has a large effect on the consumed steel of structure and finally on total cost of the project. R-Factor depends on several parameters such as Strength, Ductility, Damping and Redundancy, which are the most important parameters. According to this issue, the results show that the value of response modification factor in puzzle building frame is more than the other R-Factors in similar steel structure frames. The results of numerical analysis matched well with pushover analysis by sap2000, one of the powerful structural finite element software. As a result, the estimated value of R-Factor in PBF systems is proposed.
