In a previous study, an optimal control method was proposed for typical office space in hot and humid regions where Thermally Activated Building Systems (TABS) are installed. This method was based on a combination of load prediction, model predictive control, sparse modeling. The cooling capacity and indoor thermal environment were evaluated using computational fluid dynamics analysis and coupled MATLAB/Simulink analysis. However, that verification was conducted for one span (7.20 m×7.20 m×3.87 m) only, and verification on a larger analysis target is essential when considering implementation in actual buildings. Therefore, in this study, we proposed an optimal control method for a one-floor TABS model and verified it by co-simulation with Modelica and MATLAB/Simulink. The results showed that the proposed method improves the energy performance by reducing the integrated water flow rate while improving the control performance.