In this paper, the planning and realization of electrical installation works on the construction of a family prefabricated house is analysed in detail. The situation is monitored from the point of view of the contractor and a concrete example of a prefabricated house on which the company Elektro Tušek d.o.o. performed works. The entire process from the moment of selecting the contractor to the moment of handing over the works is described. The participants in the construction are defined and their roles are described. The process of selecting contractors through a thorough process of assessing their expertise and capabilities is described. After the selection, the process of creating a cost estimate is described, which includes all the necessary materials and works, as well as the procurement of materials that ensures the timely availability of the necessary resources for the smooth execution of the works. The execution of electrical installations, which is carried out in compliance with safety and quality standards, is explained. The purpose of the construction diary is stated, it is described how to write it and which things are important to state in it. Also listed are the documents that contain the final documentation that confirms compliance with regulations and standards. The explanations are supported by the project designed by the company Binel d.o.o. and pictures taken personally at the construction site.