Post-earthquake resilience goals underline the need for seismic design and retrofitting strategies that minimise downtime, beyond ensuring life safety alone. Current seismic codes, including the Italian NTC-18, overlook downtime-related performance metrics, implicitly accepting functional disruption and damage after moderate to severe seismic events. This study examines the seismic performance of both newly designed and retrofitted Italian reinforced concrete (RC) buildings, focusing on expected annual downtime, recovery time trajectories, and associated economic losses. To do so, four representative new RC residential buildings, designed according to NTC-18 for a high seismic hazard level, were assessed through a component-based loss assessment methodology using Multiple Stripe Analysis. Then, a representative existing RC school building from the 1960s–70s was analysed under moderate and high hazard scenarios, adopting the same loss assessment approach. For the existing building, four distinct retrofit strategies were also compared using a multi-criteria decision-making framework that encompassed economic, social, and technical decision variables. For both new and existing buildings, a recently proposed post-earthquake recovery assessment methodology was employed to assess recovery time trajectories, considering five recovery states – ranging from stability to full functionality – and accounting for different impeding factors. Results show that while modern code-compliant buildings are likely to be re-occupiable after frequent events, they may not be functional or recoverable after rare events. It is also shown that retrofit interventions significantly influence the recovery time trajectories, making the selection and optimisation of the former essential for resilience planning. Overall, the findings highlight the need to foresee downtime-based limit states in seismic codes, supporting the European objectives for sustainable and resilient built environments.