Abstract
In Europe, the debate on the recovery of the historic centres has been developed, over the years, around the balance between conservation and transformation needs in order to meet the new demands of the contemporary world. In the field of urban planning, the strictly conservative and binding approach has gradually been supported by flexible and consensual mechanisms that act as a stimulus to private initiative in the redevelopment and regeneration of the historic urban landscape. The consolidated Italian experience in the policies for the protection and enhancement of historical settlements is being significantly innovated after the entry into force of the Urbani Code, which extends the character of landscape heritage to the historic urban fabric, transferring to the regional authorities the task of establishing the specific regulations for its use and transformation. The Region of Sardinia has achieved an important role in the implementation of policies for the recovery and redevelopment of the historic centres identified by the Regional Landscape Plan (RLP). The common and consolidated practice is still characterized by the use of traditional regulative instruments, in particular the detailed plan, which provide rules for the requalification of the compromised urban fabrics through a set of rules and guidelines to be applied to the replacement of recent buildings and the renovation of urban patterns that for density, ratios between solids and voids, heights, alignments and elevations are incompatible with the values of the context. The constraint and binding approach is effective in the conservation strategies but often inadequate to implement actions of integrated redevelopment of urban fabric altered by new buildings in contrast with the historic urban landscape features, also due to the global crisis situation and the shortage of public funding. The paper proposes the use of the non-financial compensation tool, based on the granting of bonus development rights to realising on site or in alternative locations, in order to encourage urban regeneration projects that also involve the replacement of buildings incompatible with historical urban landscape morphological patterns. The integration of a methodology for assessing the financial feasibility of the demolition and reconstruction of the incompatible structures in the planning process, as tested in the case study of Villasor municipality, has allowed the elaboration of a model to support the use of a compensation mechanism for the redevelopment of historical settlement values. In this perspective, the paper aims to investigate the opportunities provided by market-oriented and flexible approaches to support and promote private urban regeneration projects. In particular, it illustrates the experimental results of a methodology for the analysis of the urban fabric that takes into account the factors influencing the feasibility of the intervention of demolition and reconstruction of the incompatible buildings. Finally a model for the assessment of any bonus in terms of additional building capacity is suggested, to be granted to private operators as an incentive to ensure the cost-effectiveness of the project.