Designing a power supply of a newly built property, investor has at his disposal whole range of technologies, skillful selection of which will minimize the total cost of supplying the facility with energy. Apart from renewable energy sources like photovoltaics, wind turbines or solar heating, classical technologies like district heating, micro/mini cogeneration unit or gas boiler can be used. For an optimal use of a complex power system, energy storages may be necessary, as well as an advanced control system. The choice of the property power supply structure is extremely important, because this decision will impact the costs that will be incurred by the owner over the next few decades. This article shows how to select the structure and parameters of power supply of residential premises, taking into account the characteristics of consumption of electricity, heat and weather conditions. The obtained solutions were analyzed depending on availability of district heating and local generation, adopted electricity tariff, as well as energy and capacity prices. The results demonstrated profitability of local generation in the form of cogeneration and wind energy for own consumption, while local generation focused on electricity sale to the grid and PV installations proved to be not economically feasible.