Electrical installations are a set of interconnected low-voltage electrical equipment in a space or facility with the task of transmitting electricity from a distribution network. Through four basic groups of electrical installations, namely power installations, lightning, telecommunication and signalling installations, energy is transferred from the distributor to the end consumers. Each electrical installation material and device has a role to play in the process, and their role is described in detail throughout the work. Power lines are listed as the basis for each installation. The illumination calculation shows the required illumination on the premises of the building, as well as the types of lamps. Electricity safeguards, as an important part of the power system, ensure the safe use of all electrical supplies powered by a low-voltage network. The type of grounding for the facility is proposed and the load calculation of one household as well as the household group is shown through the load calculation. In the practical example of a single-family house, through the plan of house and single-pole schemes, the main segments of electrical installations are shown as the sum of all the above mentioned in the final thesis.