The renovation of the residential complex of Via Brescia is one of the interventions developed within the FP7 Smart City project SINFONIA.
The building is divided in 5 staircases with 7 floors and 21 apartments each, with an overall surface of around 32,000 m3 and it is managed by IPES-WOBI, the social housing Institute of the Province of Bolzano.
The building is divided in 5 staircases with 7 floors and 21 apartments each, with an overall surface of around 32,000 m3. The complex is a typical construction from 70ies, with a reinforced concrete structure, prefabricated roof elements, wall masonry and double-glazed windows. The heating system and the domestic hot water is supplied by the city district heating, and presents a poor insulation properties.
The ambitious energy renovation fostered by SINFONIA has been implemented by IPES with the support of the Energy Agency Casaclima and Eurac research. The team worked in different phases from the design to the monitoring, and aimed to bring the yearly energy consumption of the building from 220 kWh/m2 towards less than 25 kWh/m2 considering the contribution by renewable energy sources.
To reach the target, the main interventions deal with insulation of the envelope and of the distribution system, and the energy improvements are also linked with a general upgrade of the building aesthetic, with the replacement of the external doors, windows and balconies and elimination of the thermal bridges given by the concrete frames.
The insulation of the building facade is made by an external layer of 16 cm rock wool, leading to a thermal transmittance of around 0.2 W/m2 K, while the windows are replaced with new elements with wooden frame (1.3 W/m2 K) and triple glazing (0.5 W/m2 K). It is interesting to underline that the roof (insulated towards 0.11 W/m2 K thermal transmittance) was raising of one floor with a wooden structure, creating an additional residential volume and exploiting the local incentive of “volumetric bonus”, enabling to an increase of the 20% of the building volume in case of reaching very high energy performance (class A according to the local energy labelling).
Concerning the HVAC system, the distribution has been upgraded and insulated and the heat is supplied to the apartments with radiant floors.
Moreover, the renovation includes the integration of renewable energy sources, and in particular a solar thermal plant, installed both on the Southern façade (155 m2) and on the roof (218 m2) and a photovoltaic system with a power of 260 Wp.