Sardinian regional law on suitable areas: stop by the Constitutional Court

With ruling no. 184 of 16 December 2025, the Constitutional Court, as expected, deemed the now well-known Sardinian Regional Law no. 20/2024 on suitable areas (the “Law”) to be largely unconstitutional.

Below is a summary of the main arguments put forward by the Court, together with our preliminary considerations on the implications of the ruling in question.

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On the application of the Law to authorisation procedures that have already been completed

The Court deemed unlawful the provision (Article 1, paragraph 2) of the Law that required its application also to procedures already completed. 

This provision would, in fact, violate the principles of legitimate expectations and free economic initiative, as well as that of maximum dissemination of renewable energy sources.

In the Court's opinion, the regional provision “goes beyond a regulation that unreasonably limits legitimate expectations, conflicting with the principle of legal certainty as it nullifies all authorisation measures issued for the construction and operation of plants powered by renewable sources, without this reversal being justified by technical or scientific reasons (ex plurimis, judgment no. 88 of 2025)”.

With regard to the prohibition on the construction of plants in areas classified as unsuitable

In line with the Court’s position, it was reiterated that ”unsuitability can never be equivalent to an absolute and a priori prohibition (judgment no. 134 of 2025)”.

The classification of an area as unsuitable determines, at most, the impossibility of accessing the simplified authorisation procedures provided for by the national legislator in suitable areas to speed up the spread of renewable sources.

In such areas, in fact, the installation of a plant may be authorised, but on the basis of an appropriate assessment and a reinforced justification.

According to the judges, “the final decision on the construction of RES plants in areas designated as unsuitable must, in any case, be taken at the end of the individual authorisation procedure concerning the specific plant project, within which reasons in favour of its construction could still be highlighted”.

In fact, it is during the procedure that the objective reasons preventing the construction of the plant in an unsuitable area must emerge. In the Court's opinion, the authorisation procedure allows for a concrete assessment of the relationship between suitable and unsuitable areas, as well as a complete balance between nature conservation and environmental protection through the reduction of polluting energy sources.

This approach makes it possible to counteract the Nimby phenomenon and thus prevent the wishes of certain regional political bodies seeking to obstruct the construction of plants in their respective territories from being indulged.

In light of these arguments, the provision imposing an absolute ban on the installation of RES plants in unsuitable areas was therefore declared unconstitutional.

On the limits for revamping and repowering interventions

The regional regulation introducing different types of limits on repowering and revamping activities, based both on the size of the areas concerned and, in fact, on the number of new-generation wind turbines that can be authorised, is constitutionally illegitimate due to its violation of the division of legislative powers, thus adopting a criterion that differs from and conflicts with that established by the state legislator. 

Offshore plants and state jurisdiction

The Court clarified that the identification of suitable areas for the installation of offshore RES plants falls under the jurisdiction of the Ministry of Infrastructure and Transport.

It follows that the regions, including Sardinia, cannot independently identify suitable sites for the installation of such plan.

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The Court upheld most of the objections raised by the Government against the Sardinian regional law, confirming and reinforcing the national and European approach in support of the energy transition.

In this regard, it is desirable that some of the ideas offered by the ruling in question be taken up and incorporated into the current conversion of Decree Law 175/2025 into law.

As is well known, this decree has significantly redefined the legislation on suitable areas, leaving some significant concerns, especially with regard to certain aspects examined in depth by the constitutional judges, including the absence of transitional provisions and the regulation of projects that only partially fall within unsuitable areas.

The shared objective must be to achieve a regulatory framework that is as clear and unambiguous as possible in order to prevent operators from constantly resorting to the courts to assert principles that should be undisputed.