This thesis examines the characteristics of heat cost allocators. Heat cost allocators do not measure heat energy. Instead, they determine the share of heat delivered to single consumer units in total heat consumption, measured by common heat energy meters. First, heating systems are introduced and the fundamental principles are discussed. A brief overview of different approaches to the measurement of heat consumption for billing purposes is given. The legal regulations pertaining to the installation of heat cost allocators and thermostatic radiator valves are also presented. Second, heat cost allocators are classified according to the European Standard EN 834 for the appliances with electrical energy supply and the European Standard EN 835 for the appliances without electrical energy supply based on the evaporation principle. The basic characteristics of heat cost allocators as well as the design requirements are also discussed. Furthermore, a comparative analysis of different types of heat cost allocators is made to show their respective advantages and disadvantages in use. Next, additional equipment and procedures required for proper installation of heat cost allocators are defined. Then, the steps to be taken in the process of heat cost allocator installation are described, from a decision to install the device, the selection of a company specializing in heat cost allocator installation that will carry out the task to heat consumption reading and heat energy billing. Finally, the data collected by measuring heat energy consumption during two heating seasons, one without and the other with installed heat cost allocators, are analyzed.