Stand-alone microgrids integrating renewable energy sources have emerged as an efficient energy solution for electrifying isolated sites, such as islands and remote areas. The design of a microgrid involves various influential factors, including technological development, economic feasibility, and environmental impacts, based on the conditions and regulations of a particular site. This paper proposes a comprehensive microgrid design framework based on power system analysis and techno-economic analysis. The obtained optimal microgrid configuration satisfies both the design objective and power system performance regulations. The proposed design approach focuses on using practical data and can adapt to any microgrid design problems based on the local characteristics of a specific site. The practicality and effectiveness of the design framework are validated by applying it to the design of a stand-alone microgrid for Deokjeok Island in South Korea. The case study results justify the importance of considering site-specific characteristics and the impacts of power system conditions on the optimal microgrid design.