**1. Introduction**

Nowadays, the inadequacy of public resources availability for the exploitation of unused public buildings, similarly to what happens to other sectors of the Public Administration, leads to seek for innovative solutions that allow to pursue the economic improvement of those buildings [1]: Following that purpose, some public-private partnerships might be considered useful relevant to those who work in the field of services of architecture and engineering.

Such partnerships, the need to guarantee the economic-financial balance in the processes of valorization of real estate becomes fundamental.

At the moment, the prevailing approach for such questions draws the methodological basis from disciplines dealing with the economic dynamics of companies. This approach allows us to evaluate the expected revenues properly, but it shows some weaknesses in terms of cost estimation, as it will be deepened ahead in the article.

In the last decades, the estimation culture in Italy has contributed significantly to develop methodologies and techniques economic evaluation of the projects, starting from its classical scientific base and enriching it with contributions coming from other related disciplines. It is to this relatively recent disciplinary evolution that this work intends to connect.

This contribution objective is to provide an easy-to-use tool in order to verify the feasibility and the economic sustainability of hypotheses of re-use of buildings unused public, in case it is intended to involve private subjects for the realization and/or management of the interventions. The model explained below can also be used in the case of important architectural heritage, but it is not intended for residential target or for regeneration initiatives entirely carried out by public bodies [2].

It is to be hoped that this approach can be of help to the decision-making process, from the start-up phase of the planning activity, matching with the technical and the economic feasibility project, under the Italian law.

### **Part First—Public–Private Partnerships for the Exploitation of Unused Public Buildings**
