This paper presents a comparative study on the direct seismic design methods for buckling-restrained knee-braced frames (BRKBFs) with single plate shear connections (SPSCs). Three significant methods, namely direct displacement-based design (DDBD), performance-based-plastic design (PBPD), and yield point spectra (YPS) are investigated for the seismic application of the BRKBFs. The main objectives of this study are, (1) to determine the design base shear of a BRKBF system using the three direct seismic design approaches, and (2) to bring an engineering judgment for the design of the proposed framing system under severe earthquake ground motions. Thus, a comparison between the three methods is required. First, the comparison of the design base shear determined by the three direct design approaches was conducted in order to facilitate an engineering judgment of using a suitable method for the design and evaluation of the BRKBFs. Two levels of earthquake; design basis earthquake (DBE) and maximum-considered earthquake (MCE) are investigated with a target drift of 2% and 3%, respectively. The results showed that PBPD provided the most suitable and stable design base shear at both DBE and MCE hazard levels. Second, the PBPD approach was applied to an example of 3-story, 3-bay BRKBF structure with single plate shear connections. The step-by-step design process was described and the member shapes were selected based on plastic equilibrium of the BRKBF with SPSCs system. The proposed BRKBF with SPSCs system designed using the PBPD method appeared to be a viable alternative to conventional seismic load resisting structural systems, as member shapes were engineeringly acceptable. However, it is suggested that modification of energy parameters, system testing, and performance evaluation should be further studied.