The City of Porto and its Historic Centre Facing Ecological Challenges Between threats and possible measures

Europe is preparing to implement major plans to rehabilitate and renovate the historic building, which accounts for a large share of the entire building stock. The goals are connected with the United Nations 2030 Agenda and also with continental policies to reduce CO2 emissions, about 1/3 of which come from buildings, to reduce land consumption, and more generally to achieve sustainability and apply the principles of the circular economy, in a broader logic of combating the factors that affect the causes of climate change. Restoration is in itself sustainable. The materials and technologies that are an expression of building tradition, often the most suitable for conservation, are in fact traceable to the principles of recycling and the circular economy. At a time of overwhelming transformations, what are the prospects for Restoration both with respect to the new ecological criteria, which require some theoretical and operational rethinking, and with respect to the definition of the field of competence on the unrestricted European historical building heritage, which is of great significance in terms of quantity and patrimonial value? Within this framework, as the limit of further land consumption approaches, in the logic of limiting the social costs of demolition and disposal, preservation can extend and validate itself, by virtue of proven tools and culturally oriented models. The fate of millions of Europe's historic buildings, which define the fabric of territories, require now more than ever to be preserved and adapted, in terms of use and energy efficiency, in a new logic that seems to reverse the paradigm that restoring costs more than demolishing and rebuilding.