The architectural engineering and construction sector accounts for about 30-40% of global energy consumption. The European goal of reducing this consumption and the linked greenhouse gas emissions calls for an increased capacity to implement building renovations. Building Information Modelling (BIM) and Building Performance Simulations (BPS) are among the most promising tools for fostering interdisciplinary, efficient processes and feasible analysis and design solutions to support this goal. Of the whole building stock, heritage buildings represent the most challenging part, although their potential as a driver for mitigating climate change and supporting sustainable development is being increasingly recognized. This paper presents a Heritage BIM and BPS-based workflow to support the energy and environmental improvement of publicly-owned historical buildings, that was applied to 9 case studies of 7 different Mediterranean countries. The overall aim of this research is to enhance the capacity of public local administrations and professionals to upgrade the historical building stock and demonstrate the scalability of the proposed workflow to the entire building stock of the Mediterranean area.