This study presents an experimental and a numerical analysis to decrease the effect of vibrations on buildings. A small two storey building model has been prepared in laboratory for study, consisting of steel plates and columns. Free vibration tests have been performed on the model. After interpreting the results of free vibration tests, a simulation model has been used to compare with the test results. Then, a dynamic absorber was designed for suppressing the vibrations on the model. The experimental and simulation results were compared. It is observed that the dynamic absorber suppresses vibrations on buildings. The results show that the buildings with dynamic absorber are effective in decreasing the undesired exterior effects such as earthquakes.