Energy efficiency and restoration in the historic centre of Ferrara, a view between conservation and performance

Energy retrofit of existing buildings, as is usually defined, is a widely debated issue in the literature, either in scientific or popular works. The first part of the text focuses on energy retrofit of existing building and presents a historic and critical digression of the cultural and normative approach, with special attention to its consequences on pre-industrial building, as compared also to other European experiences. The intervention on pre-industrial building in terms of energy efficiency cannot be promoted in terms of transformation and adaptation incompatible with conservation. It is necessary to promote an enhancing approach with practices and limits similar to the current ones, e.g. the reduction of seismic risk. The core part of the analysis presents various models applied to built-up areas of Ferrara pre-industrial building, as an example of historical contexts that can be widely compared with other similar Italian realities. This analysis is followed by a description of architecture, plant and functional characteristics of Ferrara building, here defined as "factors related to the pre-industrial building energy behaviour", of which we will analyse the characteristics, the energy limits and the intervention possibilities, in terms of conservation compatibility, also in relation with the different building typologies in which they are prevalent. This description in conceived as a trace for a “Guide Line for energy efficiency improvement in historic building”, especially in the historic centre of Ferrara. The last part presents a range of tools, ranging from the assessment models of large building parks (bottom-up and top-down) to quick models based on the UNI/TS 11300 calculation method, which are useful in order to manage building transformation, both at national, regional and municipal level. These data may be useful both for the allocation of public financing, for restoration and building maintenance, and the urban regulation of each Municipality, in order to regulate interventions on historic buildings