New Minimum Requirements Decree in force from 3 June 2026: here are the main changes

A single organic text

As regards the technical commitment, from an operational point of view until 2 June it was necessary to coordinate the Ministerial Decree of 26 June 2015 for casing and systems requirements, Legislative Decree 199/2021 for renewable source obligations, Legislative Decree 257/2016 for electric vehicle charging stations, Legislative Decree 102/2014 for building automation systems, Directive 2020/2184 for water quality and network separation.

From 3 June 2026 everything is incorporated into Annex 1 of the Minimum Requirements Decree 2025. The technical report pursuant to article 8 of Legislative Decree 192/2005 documents all obligations in a single location, eliminating risks of forgetfulness and automatically coordinating requirements that were previously scattered in separate regulatory texts.

Thermal bridges, from the flat rate increase to explicit values

Returning to the new calculations, the main one concerns the method to be applied for thermal bridges in the reference building. The 2015 Ministerial Decree used a flat rate increase of 5-10% on transmission losses, without distinguishing between buildings with compact or articulated architecture. The 2025 decree introduces in Appendix B eight tables with linear psi transmittance values ​​differentiated by type of discontinuity (windows, balconies, pillars, corners, inter-storey floors), climate zone and position of the insulation.

Envelope efficiency indicator, typological diversity recognized

The H’T (envelope efficiency indicator) no longer has a single limit value for climate zone and S/V ratio, but is modulated according to the percentage of glass surface of the building. Thus, for example, a tertiary building with 60% glass can have H’T limits up to 43% higher than a building with 9% glass, recognizing that even using the best available windows and doors, dispersions through transparent surfaces inevitably remain higher than those through well-insulated opaque walls. This differentiation resolves the penalization of executive buildings with large windows for natural lighting, while still maintaining the global verification on EPgl,nren.

Electric columns, retroactive obligations from 2025

The decree fully implements the European obligations on alternative fuels. For new residential buildings with more than 10 parking spaces, there is an obligation to prepare ducts for all spaces, with 1 kW available power per space.

For non-residential buildings with public car parks the obligation is for actual installation, not just preparation, with a variable number from 2 type A points for 10-25 spaces up to over 25 points for car parks exceeding 350 spaces.

Systems, from the efficiency of the components to the system balance

Finally, on the plant engineering front, the decree confirms the requirements already in force in European eco-design regulations for condensing boilers, heat pumps and biomass generators, but introduces as a novelty the explicit regulation of hybrid systems.

Instead, minimum class B building automation systems (BACS) become mandatory not only for new buildings but also for renovations and redevelopments of non-residential buildings over 290 kW of nominal power, subject to economic evaluation, which if it demonstrates payback times of less than six years makes installation mandatory even below the 290 kW threshold.

More complete technical report

The technical report provided for by article 8 of Legislative Decree 192/2005 inherits the function of article 28 of Law 10 of 1991, but with the Ministerial Decree 2025 it substantially changes its content and complexity. It is no longer sufficient to verify limit transmittances and minimum yields declared by manufacturers.

The report must document the explicit calculation of each thermal bridge with two-dimensional or three-dimensional simulations according to UNI EN ISO 10211 for the critical nodes, demonstrate compliance with the 50% renewable sources quota with calculation of photovoltaic self-consumption according to UNI/TS 11300 part 5, size the electric charging infrastructure with verification of the electrical system, calculate the needs for lighting according to UNI EN 15193 and passenger transport according to UNI/TS 11300 part 6 in non-residential buildings.

The certification software must integrate the new technical standards and manage finite element calculation methods for thermal bridges. The update becomes automatic: each new version of the UNI/TS 11300 standards applies 180 days after publication, without the need to modify the decree with a new ministerial provision.

Transitional regime

As regards the entry into force of the new obligations, a transitional regime is envisaged. For projects with qualification requested before 3 June 2026, the Ministerial Decree 06/26/2015 applies: the protocol date of the application for building permit or SCIA presentation applies, not the date of issue or start of works. If a variant that changes the energy performance is requested after June 3, 2026, even on a previous project, the variant must comply with the new requirements.

Finally, for free construction interventions (generator replacements, untitled redevelopments), the decree in force at the time of starting work or submitting the communication/CILA applies.

Comparison between the old and new Minimum Requirements Decree: table

We see in the following table a direct comparison between the obligations in force prior to the entry into force of the New Minimum Requirements Decree (DM 28 October 2025) and those in force starting from 3 June 2026: