Over the last several decades, many low energy technologies have been developed and deployed to reduce building energy consumption. Among various solutions, solar photovoltaic thermal (PVT) collectors and phase change materials (PCMs) are among the most promising methods receiving increasing attention. This paper presents a thermal performance evaluation and optimal design of buildings integrated with air-based solar PVT collectors and PCMs embedded in the building envelope by using The Hooke-Jeeves pattern search method. The Hooke-Jeeves generalized pattern search is used to search for optimal solutions of the optimization problem. The variables optimized include the PVT air flow rate, additional wall insulation and PCM layer thickness. The optimal values identified by using the Hooke-Jeeves pattern search method for the PVT air flow rate, additional wall insulation and PCM layer thickness were 1359.4 kg/h, 3.0 m2·K/W and 0.03 m, respectively. The Coefficient of Thermal Performance Enhancement (CTPE) of the house reached 72.6% when the optimal design values identified were used.