Italy expands renewable energy mandates for building renovations

New Italian regulations, stemming from the transposition of the European Union's RED III directive (Directive 2023/2413/EU), have expanded the requirements for renewable energy integration during building renovations. Effective August 3, 2026, Legislative Decree no. 5/2026 updates previous laws to include interventions that were previously exempt.

The new rules apply to second-level renovations, which involve modifying more than 25% of a building's dispersing surface (such as installing external thermal insulation or insulating roofs), as well as substantial renovations of thermal systems. For these types of projects, at least 15% of the energy required for winter heating and summer cooling must be covered by renewable sources.

Requirements vary based on the nature of the project: - New constructions and significant expansions must meet a 60% renewable energy quota for both domestic hot water and total thermal/electrical consumption. - Public buildings face higher requirements, with a 65% quota for new constructions and a 45% quota for first-level renovations. - First-level renovations require a 40% renewable energy threshold.