Energy efficiency of the Italian office buildings: Highlights from mandatory energy audits

• The energy analysis of 260 Italian office buildings and 512 retrofitting interventions. • The renovation of heat generators presents the highest savings, but also requires strong incentive support. • LED lighting is the most frequent measure due to low cost and fast payback. • Cost-effectiveness of the energy-saving measures improves with building energy intensity and size. • Public incentives reduce payback times of interventions according to the building’s pre-retrofitting state. This study analyzes the energy performance of hundreds of Italian office buildings using data from mandatory energy audits submitted by large banking and insurance companies. The database comprises 260 buildings and 512 retrofitting measures, reporting the most common strategies for reducing energy consumption and carbon emissions. Installing new heat generators presents the highest energy and emissions savings–up to 30 % – but also high upfront costs and long payback times. Retrofitting the lighting system with LED is the most frequent intervention due to its low initial costs and fast returns, typically under five years. The cost-benefit analyses show that the energy-saving potential of retrofitting interventions increases with building energy intensity and size. Retrofitting the most inefficient buildings maximizes returns, but it requires multiple interventions and the support of public incentives, such as the Conto Termico and White Certificates, to improve financial viability and reduce unit costs. Our analysis provides policymakers and stakeholders with actionable guidance on designing effective retrofit strategies and incentive programs, thereby accelerating progress toward national and European climate goals.