On the basis of technical and economic analysis the unit costs of hot water preparation were calculated for single family homes and multiplex houses, assuming the number of people from 2 to 40 at three different options of hot water consumption: 35, 45, 55 dm3/per capita. The comparative analysis used two accumulation systems for hot water preparation, i.e. a set of solar panels and a system using a gas-fired boiler. Conducted calculations have indicated the system using gas-fired boiler as the one, which in view of the assumed 15-year operating period reveals the best economic indicators, i.e. the costs of hot water preparation will be the lowest.