of technology, reducing the water heating process, results in lower CO2 emissions and the use of less energy-consuming generators. Along with this project, a system for rainwater recovery was proposed, in keeping with the idea that, in an increasingly difficult context of water resource supply and management, it is necessary and a must to adopt, both for new constructions and in already existing ones, solutions aimed at achieving acceptable levels of building sustainability. According to the present Italian legislation, rainwater, once collected, can be used to irrigate public or condominium green areas, to wash paved areas, for technological use, to fill WC flushing systems, for water distribution on underground levels and, finally, for air conditioning systems. For the work proposed in the project to modify the system, regulation Uni en 12056-3:2001 and din 1989-1:2000-12 were used as references. Therefore, during an initial phase, a study was carried out to establish the required parameters to modify the system, such as, the total rainwater flow, the catchment surface area and the runoff coefficient. Using the ex-Roma Urbe meteorological station of the Municipality IV, data on yearly rainfall levels was gathered, information necessary to calculate the total rainwater runoff in catchment surface areas7 and to evaluate the average annual rainfall. The water need was, instead, established depending on the type of use, the quality, the number of users and the quantity and type of services required, then, later the maximum volume of rainwater collected was identified and, finally, the tank sizes were estimated. As far as the positioning of the eight 10.000 litre cisterns was concerned, it was proposed to locate them in the space available at the basement level, to avoid excessively increasing the load on the overhead floors. Finally, once the monthly balance was calculated between the net volume of rainwater collected from the covered surface areas and the internal need, it was decided to use the collected water only to irrigate the green areas. In fact, the recovered water is always equal to that collected and is not sufficient to fully meet that required for other eventual uses. The actual carrying out of the work planned in the redevelopment project, which would result in a marked improvement in the whole complex’ s energy efficiency, would mean moving the families presently living in the buildings marked for renovation. Therefore, it appears evident that the management of the entire operation should forecast more phases, of which the first should be to construct a new building and its accompanying services, so that in the second phase, that concerning the work on the first two levels of Building A, the inhabitants of 32 duplex apartments would find themselves temporarily accommodated in the newly completed building. Then, the demolition of Building D could be forecasted and also the construction of the garage. The occupants of the 30 apartments in the building could be moved permanently to the new building. It would be, in fact, enough to use the apartments in Building H, one of the two tower blocks, numbering 30 dwellings, or a more homogeneous allocation of the inhabitants could be considered among the different new buildings. Also in the case of the changes foreseen for the 32 simplex apartments in Building A to be allocated to single people and / or disabled and for the neighbouring apartments which should be then modified( for a total of 64 units), the inhabitants could be transferred to the new homes on the first two levels of the same Building A( phase 1), where there would have already been completed more apartments compared to the existing number. Although quite synthetic, the project experience conducted on the Vigne Nuove settlement has shown how, in the framework of the enormous patrimony of social housing existing in Italy, it is possible to intervene8, to increase the energy efficiency of single buildings and of a whole complex through technical solutions which individuate a converging of prefabricated construction systems, features of the public building of the seventies and the present new construction methods. Often, the work carried out on social housing buildings results in marked alterations and increases in size, and, unfortunately, changes to the architectural language are all too frequent. However, in the case of complexes which over the years have become examples of a specific planning and design by groups of brilliant professionals, the approach should change, with it
Energy retrofit for Rome municipality’ s residential real estate( ATER) 711