Density and solar radiation in the historical urban fabrics: Colle Oppio neighbourhood’s case in Rome

This research aims at determining the relationships among solar radiation and urban form of historical fabrics in Mediterranean compact city, taken density as useful parameter to illustrate their features. Despite the growing unsustainability of today’s city, recent statistics have confirmed the increasing attractive power of metropolitan areas. An approach determining instruments and design methods at both urban and architectural scale, should be found in order to set out more appropriate conditions for the historical compact city. In respect of this kind of scale, the relationship between solar radiation and form takes a central role in the variation of energy performances. This comparative study investigates this relationships by models and simulations set up in order to control the correspondent factors. It is carried out for different historical morphologies existing in the Colle Oppio neighbourhood in Rome. The influence of urban morphology and built-form on solar access is shown by definitions of density indicators. Among these, are determined those more suitable to express reliable trends in relation to solar access. Built-form and typology are the main factors that occur in energy performances’ variation of urban fabrics. The investigation of these kinds of performances achieved by density parameters facilitates the comprehension of the different behaviours in each urban texture. Moreover it offers a contribution to the energy analysis instruments at urban scale and permits more efficient conditions for the built environment. Methodological structure and the determined parametrical instruments show themselves as knowledge base for aware transformations of Mediterranean compact city.