Abstract
The energy efficiency of residential buildings is crucial for sustainable urban development. Prefabricated panel apartment blocks constitute a major part of the housing stock in post-socialist countries and often suffer from significant heat loss due to outdated construction methods and inadequate insulation. This study evaluates the thermal performance of rehabilitated and non-rehabilitated prefabricated buildings in Oradea’s Ioșia Nord district. Using thermal imaging and energy simulations, we identify critical heat loss areas and assess rehabilitation strategies needed to meet Nearly Zero-Energy Building (nZEB) standards. The findings highlight key deficiencies in thermal insulation, propose targeted interventions, and offer recommendations for large-scale retrofitting strategies.