For a few recent years, KECA(Korea Electrical Contractor Association) has promoted a project to establish an electrical construction specification called Master Spec. This paper analyses the characteristics of standards-making process of the Master Spec. as an umbrella technical standard in electrical construction industry in Korea. This paper argues that even if the Master Spec. is recognized to be technical standards, the standards-making process involves both technical and social practices when viewed from social construction theory and governance perspective. This aspect of social practices in technical standards making should be well understood because various stakeholders in terms of interests, resources, and motives try to influence the process positively and negatively. KECA in responsible for enactment of the Mater Spec. should be very thoughtful in building consensus first of all among electrical contractors, managing relationship with concerned government officials, and dealing with potential deviant groups as well as in pooling expertises and developing technical knowledge needed for designing technical specification.