Monitoring of CasaNova Low Energy District: Result and Discussion

Abstract

CasaNova is a city district in the southern part of Bolzano, which consists of 950 apartments hosting about 3000 inhabitants. The apartments’ owners are both IPES, the local Institute for Social housing of South Tyrol, and some cooperatives.The approach adopted during the district's design phase included the urban planning concept, the energy concept and the architectural competitions for individual lots. The urban planning concept was developed by an interdisciplinary team coordinated by Frits van Dongen from Amsterdam. The team planned the construction of the eight “castles”, namely a built-up area consisting of three or four buildings placed around a shared green space.The energy concept includes three main objectives: (1) reducing the energy needs for heating, (2) rationalizing the use of traditional energy sources and (3) using renewable energy sources. In order to achieve such objectives, the concept was based on two levels. The first level was focused on the connection of the buildings to a district heating system with heat recovery from an incinerator. The second level defined guidelines on energy requirements for each lots. The CasaNova district was also included within the campaign “Sustainable Energy Europe (SEE)” promoted in Italy by the Ministry of Environment, Land and Sea. The City, the Province and the district itself were considered as good examples of implementation of energy efficiency and use of renewable sources to reduce CO2 emissions, at national level.As a concrete action within the partnership with the Italian Ministry of Environment, The European Academy of Bozen/Bolzano (EURAC) monitored the actual energy performance of the district, in the context of the implementation of the SEE campaign. The whole monitoring campaign was aimed to assess both the actual energy performance of buildings, comparing them with the design values (potential), and the level of indoor comfort in some sample apartments analyzed using different parameters such as the air quality, temperature and humidity.Monitoring results showed that the buildings have total primary energy consumptions very different from each other (ranging from 79 kWh/m2y to 172 kWh/m2y), and with a meaningful gap compared with the predicted ones, as calculated in the design phase, reaching in some cases values more than double (+167%). According to EURAC evaluation, the main cause of this issue has been identified in tenants’ behavior, especially on their non-optimal use and maintenance of the building and facilities. The paper shows how the buildings with simpler constructive solutions consume less energy than the complex ones. This difference, is mainly due to the difficulties encountered by the tenants on managing complex technologies in their flat, especially on mechanical ventilation. Indeed, the implementation of these technologies requires behavioral changes on those lodgers accustomed to live in the “classic” Italian house.