Energy efficiency implies lowering and saving energy consumption without ruin existing comfort of working or living in a space which is heated or cooled. With energy savings we are reducing CO₂ emissions and other greenhouse and toxic gases, especially if we get energy from fossil fuels. "Vila Garić" is a motel with a useful heated area of 1545.29 m². Requirements for heating and DHW are provided with a standard boiler on oil as a fuel. In the existing system indicators of energy efficiency doesn’t meet energy requirements of positive legislation and norms. With oil boiler change by installing condensing boiler on LPG better results would be achieved. Because of the contribution to significant increase in energy efficiency, the projected combined system of mechanical installations contributes to that goal. For significant energy savings and legally acceptable energy efficiency, it is necessary to change energy sources and to implement expensive mechanical installations. Implementation of such measures in most cases is economically unprofitable. This is the case with the project of the "Vila Garić" motel in the hotel "Vila Garić" transformation. Here is an additional justification for investing in mechanical installations with a combination of liquefied petroleum gas - heat pumps - solar collectors which will drastically reduce energy consumption by replacing oil fuel with LPG. This cost reduction is reflected in the fact that the condensing boiler on LPG as fuel will produce heat energy for heating and hot water preparation at low outside temperatures (below - 15 ° C), therefore at the most difficult winter time, while the remaining heating and preparation hot water in summer time will provide heat pumps and solar collectors. The planned increase in the number of rooms and beds on the total area of 2653.82 m² will include reduced energy consumption compared to the existing fuel oil system as an energy source in the existing facility.