As for Roma we can see that by increasing heat gain in the winter we can reduce the need for heating in winter. This is because of the high average temperature in heating period. It is possible to maintain a comfortable temperature with exploiting the suns radiation, having walls of thermal mass to store the heat, and improve indirect gains from the sun through ventilation.
For what concerns summer, it should be necessary to reduce the heat entering the building, to do this, it could be useful to study the position of the building, orientating it in a way that doesn’t get direct radiation during the hottest part of the day, or maybe reducing the openings on that specific side that faces sun. Also studying a good shading system can be helpful to improve the comfort inside, or a specific type of glass that is able to block part of the radiation, leaving a good amount of light in, so that is not necessary to use the artificial one. It is also possible to try to increase the heat losses, working on the ventilation, especially during the night. It is difficult nowadays to have just a natural ventilation system, especially if the are we consider has not strong winds phenomena, but it’s possible to install an hybrid system that helps the summer night cooling process.