Refurbish suburbs to regenerate cities: energy, architecture, and technology for housing

The essay argues for rethinking an urban development model based on unlimited growth and land consumption, highlighting how late twentieth-century residential peripheries have become areas where social vulnerability, lack of services and public space, and poor energy performance intersect. As buildings account for a substantial share of energy use, retrofitting the existing stock is presented as a key lever for decarbonisation and for reducing energy poverty. Within the context of European policies and national recovery programmes, the text advocates a shift in perspective: energy should not be regarded solely as a “domestic” issue, but as a collective aspect of urban regeneration, integrating energy efficiency and renewables and piloting Renewable Energy Communities. Three European mass-housing retrofit projects (Le Lignon, Park Hill, De Flat Kleiburg) demonstrate complementary approaches: performance upgrades compatible with heritage constraints, phased regeneration with ongoing evaluation, and participatory methods to involve residents – including forms of self-renovation – to enhance economic feasibility and social cohesion. The applied focus then shifts to Tor Bella Monaca (Rome), where integrated programmes (PUI and PINQuA) support the regeneration of the R5 sector: typological and energy retrofitting and efficiency upgrades of 1,272 dwellings (33,882 m²), the introduction of services and functions, the reactivation of open spaces, sustainable mobility measures, and the establishment of an energy community. The project also includes renewable initiatives such as the Le Torri Solar Park (554 kW, estimated to cover 95.5% of local demand), with expected impacts on energy bills and inclusion, in line with the 2030 Agenda and the DNSH principle.