Abstract:

The theme of the design of environmentally sound low-energy architectures is current, combining first-rate formal quality and expressive coherence to high performances as regards to functional adequacy and comfort and with a minimum impact on ecosystem resources along all the life-cycle.
The paper focuses on issues related to environmentally-friendly design criteria for high energy-efficient buildings, both by theoretical and applied approaches, highlighting the relationships among design choices at different scales of definition, construction process elements and performances of historical buildings.
While the regulations relating to benefits of energy-efficiency are being defined and many examples have risen to prominence as national standard it appears more and more obvious that the real bet on energy saving will have concern primarily on the upgrading of the existing buildings. The energy recovery of buildings heritage is difficult but it is a priority objective to be pursued.
The Italian building heritage is not generally energy-efficient. Not only the historic one of which it is necessary to preserve the morphological characteristics, but especially the latest one, built from the Second World War to today.
Often historic buildings are not energy-efficient in the winter because of their no-insulated envelope and the presence of heat bridge connection details, but they have discreet performances in the summer related to the massive characteristics of the building shell. The quality and performances of modern no-insulated buildings, devoid of thermal inertia envelope, is more critical. They are not sufficient energy-efficient in winter and in summer.
From this point of view, the quality of recent construction in Italy is modest and lead to problems related to increasing costs of fossil fuels used for heating and related to the definition of guidelines to limit pollutants emissions.
Strategies to upgrade the buildings heritage define the priority objectives to be pursued. To schedule the stages of retraining, it is essential to have the global vision of the issues and to control them.
The energy recovery of historical buildings should be compatible with the preservation and protection of historical, artistic and morphological characteristics of the context.
On the other side, buildings without morphological quality, located in suburbs or not historical urban areas, and residential housing need of energy renovation actions, including integration and replacement of construction elements, aiming to morphological and functional restructuring.

Keywords:

innovation, technology, energy efficiency, historical buildings, methodologies.