Photos / Technical Drawing credit: ATLAS, TASK 59 and Eurac

Prior to the renovation of Villa Castelli, it comprised one apartment which was only used during the summer.  However, thanks to the holistic renovation of the building, it can now be lived in all year around.  Villa Castelli is an example of a heritage building which has achieved a 90% energy demand reduction and demonstrates that a listed building can become a nearly zero-energy building (nZEB).

Villa Castelli dates back to the mid-19th century and is a private residential home which has been in the ownership of the Castelli family for the past 140 years.  The aim of the renovation project was to make the building more liveable for the Castelli family, as well as reducing the operating costs of the building.  As the Villa is a heritage building, the key challenge was to preserve the historic charm of the building.  Due to the conservation requirements, the appearance of the building’s facades could not be changed.  However, the windows were not deemed of heritage value, and while the original layout was kept for conservation purposes, the windows themselves were replaced with newer, highly energy efficient versions.

Due to the large rooms and overall poor performance of the building envelope, it was previously impossible to warm up the rooms during winter in a sufficient way, and so a major challenge was to increase the energy performance of the building so that it could be lived in year around.  The retrofit of Villa Castelli met the criteria of the ClimaHouse R certification (Klimahaus R/Climate House R), an energy label devised especially for the retrofit of historic buildings.  This was given as Villa Castelli achieved a 90% reduction in energy demand and adhered to all necessary conservation methods.


Principal Characteristics of the Renovation Works:

Ownership type: Private (owner occupied)
Year of construction: 1850-1899
Renovation completed: 2007
Floor area after works: 564 m²
Structure: The roof of the Villa has been completed replaced with a new laminated wood structure, with double-crimped aluminium sheets acting as the roof skin.  The windows and doors are triple glazed, filled with Argon and cased in a wood-aluminium frame.  The exterior walls are insulated from inside
Heating and energy: A heat pump with a geothermal plant (probes) supplies the production of heating and cooling and hot water.  The heat for heating is distributed to the rooms through a radiant floor system.  Electrical energy is produced with a PV-system, integrated in the roofing and not visible from outside.  Micro wind turbines installed on the roof contribute to the production of electricity.
Energy performance: 18,27 kWh/m²/y representing a 90% energy demand reduction leading to ClimaHouse R certification.
Cost of works: €1,500,000 (€2,660 m²)
Architect: Valentina Cari
Technical consultants: Oscar Stuffer