Restricted areas: no to amnesties

It is prohibited to make buildings constructed in a restricted area compliant with regulations: specifically, in an area subject to hydrogeological restrictions. The Constitutional Court has ruled again on planning matters, in judgment 100/2026, declaring unlawful a provision of the Regional Law of Sardinia 18/2025. In areas subject to hydrogeological restrictions, the absolute priority is to prevent environmental damage. For this reason, authorisation for interventions must always be granted in advance and the Regions may not provide for exceptions.

The contested provision is contained in Article 28 of the Sardinian law. This allows retroactive authorisation for works carried out on land subject to hydrogeological restrictions, both in the absence of prior authorisation and where such works do not comply with it. The condition is that these works must comply, both at the time of construction and at the time of application, with the provisions of regional law, general regulations and forestry regulations, as well as detailed forestry plans, and must not adversely affect the hydrogeological structure.

According to the constitutional judges, this mechanism ‘reduces the level of environmental protection’. The national law, in fact, permits only prior authorisation, whereas in this case it allows for a form of retrospective regularisation. For the Constitutional Court, the absence of retrospective authorisations in national law stems from the ‘pre-eminence of the essential public interest in assessing, ex ante and without exception, the compatibility of works with the protection of the land from hydrogeological instability’.

In other words, the hydrogeological protection order aims to prevent significant environmental damage ‘from which – as the judgment states – our country has often suffered, such as soil erosion, loss of stability and disruption to the water regime’. For this reason, it is not possible to ‘tolerate a retrospective assessment of the compatibility of works and alterations carried out on land subject to restrictions’. Nor can a system be introduced, by means of a regional regulation, that mirrors the dual compliance requirements for unauthorised works in the construction sector.

The fact that the Region, in this regard, claims jurisdiction over hydrogeological restrictions is irrelevant. According to the judgment, ‘it would not in any event be for the Region’ to have the power ‘to alter the characteristics of the authorisation procedure’ set out by national law, ‘for the purposes of environmental protection, which includes the necessarily preventive nature of the authorisation’. For this reason, the Court declares the constitutional illegality of Article 28.