Cooperation between public and private sector has achieved a remarkable widespread, in the Italian context, over the last two decades. Nevertheless, the increasing difficulty in accessing the capital market and the rising cost of funding sources, both noticeable over the past few years, led to a slowdown of Public–Private Partnership (PPP) initiatives. Meanwhile, the community is expressing new needs to be satisfied, such as the conversion of brownfields, the recovery of housing stock dating back to former times, as well as the refurbishment of public offices or schools.

The building sector is considered as the biggest single contributor to world energy consumption and greenhouse gas emissions. Therefore, a good understanding of the nature and structure of energy use in buildings is crucial for establishing the adequate future energy and climate change policies. Availability of the updated data is becoming increasingly important in order to allow a rigorous analysis. In this paper, recent data on the world energy consumption in both residential and commercial buildings are reported.