In this study, national and international standards and guidelines for structural sealant glazing (SSG) systems applied to glass facades were investigated to clarify design differences. The subject standards are ASTM C1401-14, European Technical Approval Guideline (ETAG) 002, ISO 28278, Industrial Standard 102 of China (JGJ 102), and Japan Architectural Standard Specification (JASS) 17. According to the survey results, the type of working load is the same among these guidelines except for seismic and impact loads, and all guidelines differ from JASS 17 in that they calculate by combined load. The handling of the inclined surface affecting the working load is different among these standards. The allowable stress degree is 0.14 MPa except for JGJ 102, but the concept of the allowable deformation ratio, such as temperature and seismic movement, is applied in different ways, and the seal limitation size in ASTM C1401-14 is approximately two times as wide as that in Japan’s guidelines, which makes Japan’s standard more restrictive. Moreover, Japan’s provisions for SSG bite and thickness are different from those of other guidelines. All guidelines specify a thickness less than or equal to the width, whereas JASS 17 also provides for a case in which the thickness is greater than or equal to the width. ETAG 002 and ISO 28278 provide calculation formulas based on insulating glass units (IGUs) that are either supported or unsupported and that can be applied to various IGU types, but the Japanese guidelines do not have an IGU evaluation formula for an SSG system. Thus, this paper proposes a new IGU evaluation formula for the hermetic seal height for IGUs used in SSG systems in Japan. The results of this study are intended to accelerate the revision of the Japanese guidelines for SSG systems and to increase their consistency with the guidelines of other countries.