An energy self sufficient villa

At the end of 2013 we worked on a villa located in the hill, characterized by a continental climate, with harsh winters and not served by gas. The owner is an informed person who wants to improve his life with an unconventional and decisive intervention, obteining an energy self sufficient house, working also on internal comfort. It’s not an old house, the building was built in 2005; nevertheless the possible improvements are evident.

The project was based on two different points:

1. to replace old gpl boilers by a new system formed by heat pump and photovoltaic system.

2. to isolate the structure to reduce energy requirement of the building: the energy produced by the new system gets independent. The entire work benefits from the 65% tax deduction

The villa is located on the Appennino, at 700 meters above sea level; in winter there is a very cold and humid climate. In this period, the house used 2 large gpl boilers with a high overall power; gpl was brought with tankers and stored in a cylinder, with high costs.

The villa has 3 floors, one of these is underground and includes box and cellar. Overall the structure is formed by 320 sqm. It’s a new building, so still in a good condition.

We started with an accurate energy diagnosis, which described us all the energy characteristics of the building, the dispersions, the thermal power involved and the costs of heating. Then we made a virtual model of the structure, simulating the effects of the proposed interventions and the relative costs of realization. We discussed with the customer to identify the best solution among different possibilities. We realized:

  • ¬†isolation of external elements, including terraces and roof;
  • installation of high performance windows:
  • photovoltaic system on the roof (10 kWp);
  • heat pump, powered by the photovoltaic system, for heating and domestic hot water;
  • thermostatic valves on the radiators to adjust the temperature in different areas, according to customers needs;
  • controlled mechanical ventilation with high efficiency heat recovery.

We added a small boiler in “back up” to use only when it is necessary to have a big quantity of water quickly.

Particular attention to the isolation of the structure: the “cappotto” was put on facades, balconies, intrados of terraces.

It was necessary to reposition the shutters on new frames (for the increase of walls), and eliminated thermal bridges.

In general, this is an important investment but, thanks to the 65% tax deductions, it is fully paid back with a return time of 10 years. In the meantime the owners live better, in a renovated house, 100% energy saving.