Passive and Semi-Active Tuned Mass Damper (SATMD) building systems are proposed to mitigate structural response due to seismic loads. A structure’s upper portion itself plays a role as a tuned mass and a viscous damper or a semi-active (SA) resetable device is adopted as a control feature for the Passive TMD (PTMD), creating a SATMD system. Two-degree-of-freedom (2-DOF) analytical studies are employed to design the prototype structural system, specify its element characteristics and determine its effectiveness for seismic response mitigation, including defining the resetable device dynamics. For the PTMD system realistic 15% and much higher optimal TMD damping ratios are compared. For the SATMD system the stiffness of the resetable device design is combined with and without rubber bearing stiffness. From the parametric results, the most effective SATMD system can be derived and then adopted as a practical control scheme. Response spectrum results using suites of earthquake are used to compare the SATMD scheme to an uncontrolled (No TMD) and an ideal passive tuned mass damper (PTMD) building system. The results from this design focused research will be utilised to assess the non-linear seismic response of realistic multi-degree-of-freedom (MDOF) structures.