JUDGMENT NO. 86

YEAR 2026

ITALIAN REPUBLIC

IN THE NAME OF THE ITALIAN PEOPLE

THE CONSTITUTIONAL COURT

composed of:

President: Giovanni AMOROSO;

Justices: Francesco VIGANÒ, Luca ANTONINI, Stefano PETITTI, Angelo BUSCEMA, Emanuela NAVARRETTA, Maria Rosaria SAN GIORGIO, Filippo PATRONI GRIFFI, Marco D’ALBERTI, Giovanni PITRUZZELLA, Antonella SCIARRONE ALIBRANDI, Massimo LUCIANI, Maria Alessandra SANDULLI, Roberto Nicola CASSINELLI, Francesco Saverio MARINI,
has issued the following

JUDGMENT

in the proceedings regarding the constitutional legitimacy of Arts. 2, 4, 6, 7, paragraph 1, letter d), 12, 14, 15, 18, paragraph 1, letter a), and 19 of the Sardinia Regional Law of 17 June 2025, no. 18 (Reorganization and coordination of regional building and urban planning regulations with the urgent provisions regarding urban planning and building simplification referred to in Decree-Law no. 69 of 29 May 2024, converted, with amendments, into Law no. 105 of 24 July 2024), initiated by the President of the Council of Ministers with an appeal notified on 12 August 2025, filed with the registry on the same date, entered under no. 31 of the 2025 appeal registry and published in the Official Gazette of the Republic no. 39, First Special Series, of the year 2025.

Having examined the notice of appearance of the Autonomous Region of Sardinia;

having heard in the public hearing of 25 March 2026 the Reporting Justice Maria Alessandra Sandulli;

having heard State Attorney Giorgio Santini for the President of the Council of Ministers, as well as Attorney Roberto Silvio Murroni for the Autonomous Region of Sardinia;

having deliberated in the chambers on 25 March 2026.

Findings of Fact

1.– By appeal notified and filed on 12 August 2025 and entered under no. 31 of the 2025 appeal registry, the President of the Council of Ministers, represented and defended by the State Attorney General, has initiated, among others, proceedings for constitutional legitimacy regarding Arts. 2, 4, 6, 7, paragraph 1, letter d), 12, 14, 15, 18, paragraph 1, letter a), and 19 of the Sardinia Regional Law of 17 June 2025, no. 18 (Reorganization and coordination of regional building and urban planning regulations with the urgent provisions regarding urban planning and building simplification referred to in Decree-Law no. 69 of 29 May 2024, converted, with amendments, into Law no. 105 of 24 July 2024), alleging the violation of multiple constitutional and interposed parameters.

The appellant, as a premise to the articulation of the grievances, recalls that the legislative competence in the matter of building and urban planning, granted to the Autonomous Region of Sardinia by Art. 3, letter f), of Constitutional Law no. 3 of 26 February 1948 (Special Statute for Sardinia), cannot translate into full and unconditional regulatory autonomy. In this regard, it refers to the consistent jurisprudence of this Court, according to which regions with special statutes (and autonomous provinces) are bound to respect principles and transversal matters, among which stand out "economic-social reforms of national interest, the civil legal system [...] and the determination of the Essential Levels of Services (LEP) concerning civil and social rights."

The challenged regional provisions allegedly infringe upon the aforementioned "mandatory limits, violating principles of legal system coherence and the protection of fundamental rights which, by their nature, require uniform discipline across the national territory, even in the face of strengthened regional autonomies."

1.1.– Having made these general considerations, the President of the Council of Ministers challenges, with the first ground of appeal, Art. 2 of Sardinia Regional Law no. 18 of 2025, which introduces, among others, Art. 2-bis into the Sardinia Regional Law no. 23 of 11 October 1985 (Regional rules for the control of urban building activity).

The claim of unconstitutionality particularly concerns paragraph 3 of the new Art. 2-bis, which states that "[f]or the purposes of a correct application of the definitions referred to in paragraph 1, the creation of new volume in an existing construction is considered building renovation if it occurs within the existing outline, and new construction otherwise."

The appellant observes preliminarily that, based on the combined provisions of Arts. 3, paragraph 1, letter d), and 10, paragraph 1, letter a), of Presidential Decree no. 380 of 6 June 2001, containing the "Consolidated Act of legislative and regulatory provisions on building (Text A)" (hereinafter, TUEd or Consolidated Act on Building), the realization of volumes "outside the outline" would in any case fall under new construction interventions and, therefore, would always require a building permit pursuant to Art. 10, paragraph 1, letter a) TUEd; conversely, the realization of volumes "within the outline" would not constitute an intervention type qualifyable, always and in any case, as building renovation.

This reconstruction finds confirmation also in the jurisprudence of legitimacy, according to which volumetric changes, provided for by the cited Art. 10, paragraph 1, letter a), for building renovation activities, must consist of modest volumetric increases, since otherwise the line of distinction between building renovation and new construction would vanish (Court of Cassation, Third Criminal Section, judgments no. 43530 of 28 March-24 October 2019, no. 38611 of 4 June-18 September 2019, and no. 47046 of 26 October-19 December 2007).

Having premised this, the State Attorney General deems the challenged Art. 2, in relevant part, constitutionally illegitimate, as, by qualifying the volume expansion "within the outline" as a building renovation intervention, it would introduce an automatism in clear contrast with the provisions referred to in Arts. 3, paragraph 1, letter d), and 10, paragraph 1, letter a), TUEd, which constitute fundamental norms of economic-social reform (see this Court's judgments no. 22 of 2025, no. 147 and no. 90 of 2023). The cited state norms, in fact, responding to a unitary interest that demands homogeneous treatment throughout the national territory (see this Court's judgment no. 198 of 2018), bind even regions with special autonomy, which, like the respondent, hold primary legislative competence in the matter of building and urban planning.

The challenged provision, therefore, allegedly violated the primary legislative competence of the Autonomous Region of Sardinia, as delineated by Art. 3 of the Special Statute, and the exclusive legislative competence of the State referred to in Art. 117, second paragraph, letters m) and s), of the Constitution.

1.1.1.– Art. 2 of Sardinia Regional Law no. 18 of 2025 is also alleged to be constitutionally illegitimate insofar as it introduces Art. 2-bis, paragraph 5, into Sardinia Regional Law no. 23 of 1985, which would allow demolition and reconstruction interventions in homogeneous zones A or in zones of particular historical or artistic value, in derogation from what is prescribed by Art. 2-bis, paragraph 1-ter, TUEd, according to which the reconstruction intervention within the legitimately pre-existing distances can be directly realized by the interested parties "exclusively" if contemplated "within the scope of detailed urban recovery and redevelopment plans, under municipal competence," while in any case upholding "the provisions of current territorial, landscape and urban planning instruments and the opinions of the bodies responsible for protection."

The challenged regional provision, in allowing interested parties to directly carry out demolition and reconstruction interventions in the aforementioned zones, would derogate from state discipline regarding compliance with detailed plans and territorial, landscape and urban planning, substantially stripping competent administrations of their territorial planning powers.

The Sardinian legislator would thus have exceeded the limits of its primary legislative competence and would have also violated Art. 117, second paragraph, letter s), of the Constitution, as well as the principles of reasonableness and good administration referred to in Arts. 3 and 97 of the Constitution.

1.2.– The President of the Council of Ministers, with the second ground of appeal, challenges Art. 2 of the cited regional law, also where it introduces Art. 2-ter, paragraph 2, into Sardinia Regional Law no. 23 of 1985, which, in the first sentence, provides that for properties subject to building amnesty, only ordinary maintenance, extraordinary maintenance, restoration and conservative rehabilitation, and building renovation not involving demolition and reconstruction with a different outline are permitted, without volumetric or covered surface area increase.

This provision would introduce an "obstructive 'constraint'" to the execution of interventions on buildings or real estate units subject to building amnesty and would not be compliant with what is provided by Art. 9-bis, paragraph 1-bis, TUEd, which constitutes a fundamental norm of economic-social reform. In the appellant's view, this latter paragraph – most recently amended by Decree-Law no. 69 of 29 May 2024 (Urgent provisions regarding building and urban planning simplification), converted, with amendments, into Law no. 105 of 24 July 2024 (so-called "Save Home" decree) – establishes that the legitimate status of the building or real estate unit is, for what concerns us here, "that established by the enabling title [...] which legitimized" its construction, as well as that issued following an amnesty, which, like the certificate of compliance, would constitute (as should be deduced from what was stated by this Court in judgment no. 119 of 2024) the prerequisite for the execution of any further building intervention.

The Region, therefore, allegedly exceeded the areas reserved by the Statute to its primary legislative competence in the matter of building and urban planning, also violating Art. 117, second paragraph, letter s), of the Constitution.

The challenged regional provision, furthermore, would violate Art. 42, second paragraph, of the Constitution, due to the prejudice caused to the private property owner who, even though not expropriated of the relative title, sees limited the power to carry out certain building interventions (see this Court's judgments no. 238 of 2000 and no. 529 of 1995).

1.3.– Art. 4 of Sardinia Regional Law no. 18 of 2025 is then challenged, with the third ground of appeal, in the part where, introducing paragraph 3-bis into Art. 3-bis of Sardinia Regional Law no. 23 of 1985, it provides that, both in the case of energy requalification interventions on buildings existing at the date of 24 May 2024, and in the case of new construction buildings or expansion of existing ones, derogations from regional regulations or municipal building codes are allowed under certain conditions, also with reference to the minimum protection distances for the railway line.

The challenged regional norm would specifically conflict with Arts. 49 and 60 of Presidential Decree no. 753 of 11 July 1980 (New regulations regarding police, safety and regularity of the operation of railways and other transport services).

The appellant recalls that the former provides that "Along the tracks of railway lines it is forbidden to build, reconstruct or expand buildings or structures of any kind at a distance, to be measured in horizontal projection, less than thirty meters from the boundary of the occupation zone of the nearest rail," while the cited Art. 60 allows for the derogability of legal distances from the boundary of the occupation zone of the nearest rail, but requires that said derogation be previously authorized by the Italian Railway Network Company "When public safety, the conservation of railways, the nature of the terrain and particular local circumstances allow it," upon request of the interested parties, upon whom the burden would fall to demonstrate the peculiarity of the needs that led them to provide for smaller distances and the absence of concrete risks, proven by "precise and documented safety guarantees."

The State Attorney General deduces that the provisions contained in the aforementioned articles, on one hand, should be qualified as fundamental norms of economic-social reform, and, on the other, would delineate an instrument for safety protection. The Sardinian legislator would, therefore, have violated both Art. 3 of the Special Statute, exceeding its primary legislative competence in the matter of building and urban planning, and the exclusive state legislative competence in the matter of public order and security, referred to in Art. 117, second paragraph, letter h), of the Constitution.

1.4.– The same Art. 4 of Sardinia Regional Law no. 18 of 2025 is challenged, with the fourth ground of appeal, also in the part where it introduces paragraph 3-ter into the cited Art. 3-bis of Sardinia Regional Law no. 23 of 1985, which excludes from the calculation of building volume and maximum height the thickness of external walls, and superior and inferior closure elements that enclose the heated volume of surfaces and coverage ratios, within the limits indicated therein, relating to energy efficiency interventions, even for new buildings.

Such provision would conflict with the state discipline resulting from the repeal of Art. 14, paragraph 6, of Legislative Decree no. 102 of 4 July 2014 (Implementation of Directive 2012/27/EU on energy efficiency, amending Directives 2009/125/EC and 2010/30/EU and repealing Directives 2004/8/EC and 2006/32/EC), which occurred via Art. 13, paragraph 1, letter a), of Legislative Decree no. 73 of 14 July 2020, containing "Implementation of Directive (EU) 2018/2002 amending Directive 2012/27/EU on energy efficiency."

Due to the referenced repeal, in fact, the exclusions contemplated by the challenged regional norm could not apply also to new buildings.

The State Attorney General adds that, regarding derogations ex lege to wall thicknesses referred to in the Decree of the Minister of Public Works, in concert with the Minister of the Interior, no. 1444 of 2 April 1968 (Mandatory limits of building density, height, distance between buildings and maximum ratios between spaces intended for residential and productive settlements and public spaces or spaces reserved for collective activities, public greenery or parking to be observed for the purposes of the formation of new urban planning instruments or the revision of existing ones, pursuant to Art. 17 of Law no. 765 of 6 August 1967), this Court would have affirmed its constitutional legitimacy only with reference to the limits established by local discipline.

Therefore, the challenged norm, in not distinguishing between new buildings and existing buildings, would violate, in the first place, the principle of loyal cooperation referred to in Arts. 5 and 120 of the Constitution, due to non-compliance with the obligation of concerted and shared planning, necessary for orderly urban development and for identifying transformations compatible with the prescriptions dictated by Legislative Decree no. 42 of 22 January 2004 (Code of Cultural Heritage and Landscape, pursuant to Article 10 of Law no. 137 of 6 July 2002). In the second place, the challenged regional discipline would invade the exclusive state legislative competence in the matter of civil law, referred to in Art. 117, second paragraph, letter l), of the Constitution, since it would introduce derogations "of such significance that, if allowed, they would undermine the essence and function of the planning principle underlying even the intervention of the 2020 state legislator."

1.5.– The President of the Council of Ministers, with the fifth ground of appeal, then challenges Art. 6 of the challenged regional law, in the part where, by fully replacing Art. 4 of Sardinia Regional Law no. 23 of 1985, it introduced, in paragraph 2, a quantitative notion of total non-compliance with the enabling title, diverging from Art. 31, paragraph 1, TUEd, which defines abuse in exclusively qualitative terms, and from Art. 32, paragraph 1, of the same consolidated act, which attributes to regional legislation solely the competence to determine essential variations from the title, while maintaining itself, moreover, within the parameters specifically indicated in letters a) to e).

On the other hand, the challenged Art. 4, paragraph 2, would interfere with the choices of principle made regarding amnesty by the state legislator, who refers interventions constituting essential variations to the regime referred to in Art. 36-bis TUEd, while subjecting those carried out in total non-compliance to the stricter regime delineated by Art. 36 of the same consolidated act.

Having premised this, in the first place, the appellant deduces that the challenged regional amendment, by conflicting with the referenced state provisions, which would represent fundamental norms of economic-social reform, would have violated both the primary legislative competence in the matter of building and urban planning, attributed to the Region by its special statute, and the exclusive state legislative competence referred to in Art. 117, second paragraph, letter s), of the Constitution.

In the second place, the challenged regional regulation would also have affected the identification of criminal offenses, "determining a substantial modification of the criminal law profiles connected to the realization of interventions in the absence or total non-compliance with the building title," with the consequent violation of the exclusive state legislative competence in the matter of criminal law, referred to in Art. 117, second paragraph, letter l), of the Constitution.

1.6.– With the sixth ground of appeal, Art. 7, paragraph 1, letter d), of Sardinia Regional Law no. 18 of 2025 is also challenged, where it introduces paragraph 1-bis into Art. 5 of the cited regional law no. 23 of 1985.

The cited paragraph 1-bis, in qualifying as partial non-compliance with the approved project those divergences that do not reach the levels set for essential variations and, in the case of modifications of the location of the building within the relevant urban plot, deriving from rotation on any axis or from translation, "variations [...] greater than 50 percent," would conflict with Art. 34 TUEd, which does not provide for quantitative or qualitative criteria for the definition of cases falling within the aforementioned category.

The State defense, recalling the grounds spent in relation to the challenged Art. 6, believes that it is precluded for the regional legislator to identify the notion of partial non-compliance by indicating quantitative limits, which would circumscribe the scope of the abusive conduct, with effects also on the side of the criminal sanction.

The challenged Art. 7, in relevant part, would conflict with the cited state provision, to be considered a fundamental norm of economic-social reform, and would violate the exclusive state legislative competencies referred to in Art. 117, second paragraph, letters l), in the matter of criminal law, and s), of the Constitution.

1.7.– With the seventh ground of appeal, the President of the Council of Ministers alleges the constitutional illegitimacy of Art. 12 of the challenged regional law, in the part where, by replacing Art. 7-quater of Sardinia Regional Law no. 23 of 1985, it modifies paragraph 1, regarding minimum hygienic-sanitary building requirements. This latter provision would be constitutionally illegitimate where it provides that in matters of habitability of properties and hygienic-sanitary requirements, the derogating discipline referred to in paragraphs 5-bis, 5-ter and 5-quater of Art. 24 TUEd does not find application.

The State complains that, based on this exclusion, the Autonomous Region of Sardinia would not have transposed the new state provisions – described precisely in the appeal – on the minimum surface area of housing, even though they are an expression of fundamental norms of economic-social reform as well as essential levels of service, referred to in Art. 117, second paragraph, letter m), of the Constitution, keeping "unaltered the minimum measures of habitability for studio apartments within the limits set by the national legislation prior" to Decree-Law no. 69 of 2024, as converted.

In the appellant's opinion, the challenged Art. 12, in relevant part, by not transposing the discipline referred to in the mentioned paragraphs 5-bis, 5-ter and 5-quater of Art. 24 of the Consolidated Act on Building, would be constitutionally illegitimate in that the matter relating to building standards would be configured "as an essential level of service concerning civil and social rights that must be guaranteed throughout the national territory, not being able to admit – on aspects of primary social and economic importance – a fragmentary and diversified discipline of the sector."

1.7.1.– The State Attorney General complains, furthermore, that the regional legislator, still with the challenged Art. 12, in amending Art. 7-quater, paragraphs 3, letters a) and e), and 6, would admit "for the purposes of habitability, generalized derogations from air-lighting ratios referred to in the Decree of the Minister of Health of 5 July 1975, implementing articles 218 and 221 of Royal Decree no. 1265/1934, which establishes the standards placed to protect the right to health protection referred to in Article 32 of the Constitution."

The derogation in question, being able to interest, "without even [the setting of] a minimum measure," all properties pre-existing and subsequent to the date of entry into force of the Decree of the Minister of Health of 5 July 1975 (Amendments to the ministerial instructions of 20 June 1896, regarding minimum height and main hygienic-sanitary requirements of residential premises) and those existing at the date of 24 May 2024, would violate Art. 32 of the Constitution, in that it would conflict with the interposed parameters represented by the provisions of the aforementioned ministerial decree, which, as this Court would have clarified with judgment no. 119 of 2024, would be binding for regional legislation.

The prescriptions regarding air-lighting parameters (like those on the internal height of buildings) would, in fact, pursue the essential purpose of conforming building activity and ensuring the right to health in the context of housing.

1.8.– The President of the Council of Ministers, with the eighth ground of appeal, also challenges Art. 14 of the challenged regional law, in the part where it "makes amendments to Article 11 of regional law no. 23 of 1985, regarding urban-relevant functional categories and intended use, not transposing the innovations introduced by Decree-Law no. 69 of 2024 to Article 23-ter of the TUEd," whose discipline – aimed at facilitating, through the introduction of substantive and procedural simplifications, changes of intended use, even in case of simultaneous execution of building works – is analytically described in the appeal.

Recalling that, pursuant to its paragraph 3, the discipline provided by Art. 23-ter TUEd finds "in any case direct application," the State believes that the challenged Art. 14, by not transposing the simplifications concerning the change of intended use introduced by the cited Art. 23-ter, is constitutionally illegitimate because it would violate the limits on the Region's primary legislative power and would also conflict with Art. 117, second paragraph, letter s), of the Constitution.

1.9.– Art. 18, paragraph 1, letter a), of Sardinia Regional Law no. 18 of 2025 is also challenged, with the ninth ground of appeal, which, modifying Art. 15-quater of Sardinia Regional Law no. 23 of 1985, provides, in the new paragraph 1, that "In changes of intended use that are not urbanistically relevant, without prejudice to compliance with parking spaces provided for by specific sector regulations, the municipal urban planning instrument determines the parking spaces deemed necessary."

This provision also would not be compliant with Art. 23-ter, paragraph 1-bis, TUEd and would be constitutionally illegitimate, for the same reasons illustrated in the previous ground of appeal.

1.10.– With the tenth ground of appeal, the constitutional illegitimacy of Art. 15 of the challenged regional law, which modifies Art. 14 of Sardinia Regional Law no. 23 of 1985, is then alleged.

In the State Attorney General's opinion, even in the amended text, this latter provision would continue, indeed, to provide, in paragraph 2, for works carried out in the absence of a certified notification of commencement of activity (SCIA) or in non-compliance with it, a form of amnesty conditional on the payment of a pecuniary sanction of 500 euros and the payment of construction fees, where due, according to a procedural mechanism similar to that already provided for by Art. 37, paragraph 4, TUEd, repealed by Decree-Law no. 69 of 2024, as converted.

It is deduced that the regional legislator, by so providing, would not have transposed "the new structure" of the certificate of compliance for works carried out in the absence or total non-compliance with the SCIA, currently regulated by Art. 36-bis TUEd.

Having premised this, the President of the Council of Ministers, recalling that according to the jurisprudence of this Court the provisions regarding building amnesty would be of exclusive state competence (see judgments no. 22 of 2025 and no. 77 of 2021) and would constitute fundamental norms of economic-social reform to which the Autonomous Region of Sardinia must conform in the exercise of its primary legislative competence in the matter of building and urban planning, deems the challenged regional provision constitutionally illegitimate because it would have overstepped the aforementioned statutory competence and would also have violated Art. 117, second paragraph, letter s), of the Constitution.

1.11.– With the eleventh ground of appeal, the State alleges the constitutional illegitimacy of Art. 19 of the challenged regional law, where, modifying Art. 16 of Sardinia Regional Law no. 23 of 1985, it provides, in paragraph 3, the possibility, in order to achieve the certificate of compliance for works carried out in the absence of a building permit or in total non-compliance with it, to execute the necessary interventions to ensure compliance conditions.

Such possibility would not be contemplated by Art. 36 TUEd which, instead, would require the "double compliance" of the property with urban planning and building discipline both at the moment of the realization of the abuse and at the moment of the submission of the application.

The cited state provision, "in delimiting the prerequisites and limits of the amnesty, only 'formal,' for the case of absence or total non-compliance with the building permit" and integrating a fundamental norm of economic-social reform, would bind the primary legislative power of the Autonomous Region of Sardinia.

The challenged regional provision would therefore be constitutionally illegitimate for the Sardinian legislator having exceeded its statutory competencies and, in consideration of the extinctive effect of the amnesty on the crime, also for having violated the exclusive state legislative competence in the matter of criminal law, referred to in Art. 117, second paragraph, letter l), of the Constitution.

2.– By document filed on 22 September 2025, the Autonomous Region of Sardinia entered an appearance in the proceedings, requesting that the issues be declared inadmissible or in any case unfounded.

As a premise, the respondent deduces that the appeal would start from an erroneous interpretive approach.

In the first place, it would aim to disavow the primary legislative power attributed to the Region by Art. 3, letter f), of its own Special Statute in the matter of building and urban planning, which, even in compliance with the limits proper to the constitutional legal system, including fundamental norms of economic-social reform, could not be compressed by the "slavish transposition of state legislation." This being the case, the regional defense remarks that the challenged regional law would fit into a context of coordination and simplification similar to that of Decree-Law no. 69 of 2024, as converted, whose principles have been adapted to the peculiar needs of the Sardinian territory, moreover raising, in various provisions, the level of protection of the same values in defense of the environment and the building and landscape context of the Region.

It believes, then, that the grievances are the result of an a priori reading of the category of fundamental norms of economic-social reform, not in line with what was stated by this Court's jurisprudence (see judgments no. 22 of 2025, no. 447 and no. 51 of 2006).

Since, then, fundamental norms of economic-social reform – which, the regional defense always recalls, must not be confused with the fundamental principles of the matter for ordinary regions – constitute exceptions to the exercise of full primary autonomy defined in the Statute, it would not be sufficient, as constitutional jurisprudence would still have clarified (judgments no. 22 of 2025, no. 125 of 2024, no. 90 and no. 147 of 2023 and 198 of 2018), to invoke the TUEd in bulk to support the constitutional illegitimacy of regional norms. And it adds that the regional legislator would in any case retain the power to adapt state legislation to the regional context.

Having clarified this, the respondent highlights that the challenged law, by providing mainly for dynamic references and technical specifications, would not reduce the areas of state competence and, even when it seems to indirectly affect profiles of exclusive legislative power of the State (railway safety, criminal and civil law), the limits set by the latter would be respected, since the Sardinian legislator "intends [to] operate on the mere (building) urban-procedural level."

2.1.– Having premised this, the Region believes that the issue concerning Art. 2 of Sardinia Regional Law no. 18 of 2025, in the part where it introduces Art. 2-bis, paragraph 3, into Sardinia Regional Law no. 23 of 1985, is in the first place – in light of the constant jurisprudence of this Court, widely recalled – inadmissible, as not adequately motivated.

On this point, the respondent deduces that the State would have generically alleged the conflict between the challenged regional norm and Arts. 3, paragraph 1, letter d), and 10, paragraph 1, letter c), TUEd, regarding which the category of essential levels of service would have been invoked, equally generically, and without adequate motivation.

In this regard, observes the regional defense, the conflict with state legislation "would not exist" even with reference to the discipline of enabling titles, given that Art. 3 of Sardinia Regional Law no. 23 of 1985 requires a building permit both for building renovation interventions and for those of new construction. Consequently, in the Sardinian regional legal system, interventions for which the volume increase "should not be 'certainly contained'" would be subjected to the same enabling title required for such cases by Art. 10, paragraph 1, letter c), TUEd.

The respondent adds that the issue would in any case be unfounded.

In the Region's opinion, the State would be moving from an erroneous premise in identifying the conflict with the TUEd.

If, in fact, pursuant to Art. 3, paragraph 1, letter e), of the cited consolidated act, new construction is "the construction of building artifacts above or below ground, or the expansion of existing ones outside the existing outline," it should be concluded that an intervention that is not "new construction," but implies the realization of new volumes, never realizable in the two forms of ordinary and extraordinary maintenance, could only be logically included in building renovation.

Moreover – the regional defense still recalls –, the expansion within the outline, whose definition is given by the Uniform Definitions Framework (published in the Official Gazette, general series, of 16 November 2016, no. 268-Annex A), by definition, could only have a reduced volumetric entity.

If then one were to consider that the distinction between renovation and new construction would not be clear even in state legislation, it should be recognized that the regional one is a choice of merit, not unreasonable, as it is aimed at favoring the redevelopment of existing building stock without consumption of new land, and entirely legitimate, as an expression of primary regional legislative power in the matter of building and urban planning.

2.1.1.– Also the issue relating to Art. 2-bis, paragraph 5, of Sardinia Regional Law no. 23 of 1985, introduced by Art. 2 of the challenged regional law, due to conflict with Art. 2-bis, paragraph 1, TUEd, would be in the first place inadmissible as not adequately motivated.

On the merits, the regional defense believes that the grievance is unfounded, as it would move from an erroneous and partial reconstruction, which would not take into account the overall regional regulatory framework.

First of all, the respondent notes that the challenged norm would introduce a stricter discipline than the state one regarding compliance with minimum distances in case of demolition and reconstruction, in that not only would it have provided, where there is sufficient space in the plot, for the obligation of adjustment to the minimum distances set by state legislation, but it would have allowed, on the other hand, the maintenance of the original footprint area only if the dimensions of the relevant plot do not allow for the movement of the building.

Having clarified this, it is deduced that the need for protection of historical urban contexts, through the adoption of a detailed plan, would already be provided for by the overall regional protection system, and in particular by Art. 52 of the Technical Implementation Rules of the Regional Landscape Plan, based on which interventions, like those under discussion, in urban zones A and in historical centers should in any case necessarily be contemplated in a detailed plan "of public initiative, which in turn must be approved by the Region itself, Landscape Protection Service, as precisely provided by DPR no. 380/2001."

In other words, the challenged norm would not eliminate the need for detailed planning in historical centers, but would favor an operational solution fully falling within regional legislative competence in the matter of territorial governance and within the scope of an overall (legislative and regional planning) discipline of protection and respect for local planning competencies.

In any case, the government grievance would be overly generic, as would also be confirmed by the apodictic allegation of conflict also with the principles of reasonableness and good administration referred to in Arts. 3 and 97 of the Constitution.

2.2.– As for the issue concerning Art. 2 of Sardinia Regional Law no. 18 of 2025, in the part where it inserted Art. 2-ter, paragraph 2, into Sardinia Regional Law no. 23 of 1985, this would be in the first place inadmissible due to the generic nature of the grievances.

In the respondent's opinion, both the qualification of Art. 9-bis, paragraph 1-bis, TUEd, as a fundamental norm of economic-social reform, and the assertion that the limitation of one of the multiple faculties exercisable as an owner entails the "emptying of the content of his right in the most irremediable and definitive way," would be apodictic, especially since it would not be adequately clarified why, in the face of the possibility of carrying out ordinary and extraordinary maintenance, restoration and conservative rehabilitation, or building renovation of a property, only the volumetric and covered surface area increase would constitute the type of intervention that allows avoiding the degradation and decay of the asset.

The grievances would also be unfounded.

First of all, the challenged norm would have introduced a stricter discipline than the state one, aimed at conforming the regional legal system to the principles governing the extraordinary discipline of building amnesty and its effects, continuing to preserve local planning competencies and to protect overriding public interests, such as landscape protection and territorial structure, thereby making an entirely legitimate choice pursuant to Art. 42, second paragraph, of the Constitution.

With specific reference to the alleged violation of this latter parameter, the respondent deduces that the conflict would be non-existent, as evidenced both by constitutional jurisprudence (judgments no. 238 of 2000 and no. 529 of 1995) and by that of the Council of State (Sixth Section, judgment no. 482 of 22 January 2025).

2.3.– The issue concerning Art. 4 of the cited regional law, in the part where, by introducing Art. 3-bis, paragraph 3-bis, into Sardinia Regional Law no. 23 of 1985, it derogates from the minimum distance for the railway line, would also be unfounded.

The respondent notes, in fact, that the aforementioned regional norm would not have introduced any automatism, because the discipline referred to in Arts. 49 and 60 of P.D. no. 753 of 1980 would in any case find application, thus leaving unchanged the procedure and the competence for authorization provided therein.

2.4.– The issue of constitutional legitimacy of Art. 4 in the part where it introduces Art. 3-bis, paragraph 3-ter, into Sardinia Regional Law no. 23 of 1985 would also be inadmissible and unfounded.

The grievance would be inadmissible as not adequately motivated, since the appellant would have noted the mere conflict with current state legislation and would have recalled, in a generic and apodictic manner, constitutional jurisprudence on the legitimacy of regional derogations ex lege to wall thicknesses referred to in Ministerial Decree no. 1444 of 1968.

On the merits, the grievance would be unfounded.

Not only because, the Region having primary legislative competence in the matter of building and urban planning, M.D. no. 1444 of 1968 could not find "slavish application," but also because the derogation provided, for a maximum of 30 centimeters, would have a very limited scope and would in any case not be suitable to compromise orderly urban development, nor to affect landscape protection, it not even being clear what the legal assets of state interest potentially harmed could concretely be.

2.5.– The grievance regarding the challenged Art. 6, with which the appellant alleges the radical contrast between regional criteria and national ones for the purposes of qualifying total non-compliance with the building permit, would also be unfounded, in that the alleged divergence from the invoked Arts. 31, paragraph 1, and 32, paragraph 1, TUEd, would be non-existent and the regional and national criteria in question would exist in a relationship of close integration, not of contrast.

The respondent deduces, in fact, that interventions in total non-compliance would be identified based on a qualitative evaluation identical to the state one, as demonstrated by Art. 4, paragraph 1, of Sardinia Regional Law no. 23 of 1985, which reproduces exactly paragraph 1 of Art. 31 TUEd. To this provision would be added the quantitative one of paragraph 2 of the cited Art. 4, specifically contested, according to which interventions that have entailed volumetric and/or covered surface area increases or modification of the position in the plot to the extent identified by the challenged provision itself, regardless of any qualitative evaluation, must be considered in total non-compliance. This, moreover, would allow standardizing the behaviors of the technical offices of Sardinian municipalities.

The regional choice, finally, would fit – in the respondent's opinion – into a practice widely followed by all Italian regions (also ordinary ones), as demonstrated by the publication of the National Association of Building Constructors "Essential variations: regional regulatory framework, 21 March 2025," where account is given of the fact that all regions would have identified quantitative limits to define essential variations.

The respondent then deduces that there would be no violation of state legislation on the amnesty procedure referred to in Arts. 36 and 36-bis TUEd, given that such legislation would be reproduced "in a slavish manner" by the challenged regional norm, which, on the other hand, would have no incidence "on the criminal law side, given that the criminal judge evaluates the 'urban/building' crime regardless of any administrative evaluation."

2.6.– The grievance of Art. 7, paragraph 1, letter d), of the challenged regional law would also be unfounded, for the same reasons exposed in the previous point, having been proposed by the President of the Council of Ministers for the same reasons.

The respondent adds that regions, being able to define, also quantitatively – by force of Art. 32, paragraph 1, TUEd – essential variations from the approved project, should be able, implicitly and necessarily, to define also partial non-compliance. By following the appellant's perspective, one would end up, in fact, by annulling, in practice, the regional legislative competence recognized by the same consolidated act.

Without considering – the Region concludes on the point – that the challenged norms were already all present in the previous version of the cited Sardinia Regional Law no. 23 of 1985, the challenged norm having modified only the numerical values.

2.7.– Also the issue relating to Art. 12 of Sardinia Regional Law no. 18 of 2025 would be inadmissible and unfounded.

2.7.1.– The respondent's defense observes that the challenged norm would have, substantially, failed to transpose the minimum measures of the single-room housing, while in matters of height it would have "derogated" only for buildings realized by the date of entry into force of Decree-Law no. 69 of 2024, as converted.

According to the Region, moreover, contrary to what is claimed by the appellant, the derogations to M.D. of 5 July 1975 provided for by this latter decree-law could not be qualified as a "fundamental principle," being the result of "mere political evaluations."

To this the regional defense adds, on one hand, that from the reports of the National Institute of Statistics (ISTAT), it would emerge in an "objectiv[e] and unequivocabl[e]" manner that in Sardinia "the problem of micro-housing" would not arise and that "the choice made by the regional legislator constitutes nothing but ordinary, minimal specification of national legislation in relation to the specificities of the territory"; and on the other hand, that by following the appellant's interpretation, the increase in the minimum surface area of housing, which would always have been allowed to municipal administrations (see Council of State, Fourth Section, judgment no. 747 of 17 February 2014), would not be possible for a region with a special statute in the exercise of its primary legislative competence, even though the same choice is widely justified by objective data relating to the demographic and housing situation.

The respondent observes, lastly, that the state legislation recalled as an interposed parameter would be irrational, if not illegitimate.

On one hand, because the State could not have introduced derogations like those provided for by the state norms invoked as grounds for the challenge without modifying M.D. of 5 July 1975, which would constitute "by explicit admission of the same appellant State," a "fundamental principle."

On the other, because the "alternative solutions suitable for ensuring [...] suitable hygienic-sanitary conditions of the housing," in consideration of which the qualified professional could declare habitability, are not adequately identified, thus preventing the certain and uniform evaluation of alternative design solutions.

2.7.2.– Inadmissible and in any case unfounded would also be the grievance of the same Art. 12 regarding air-lighting requirements.

First of all, the regional defense remarks that it would not correspond to the truth that paragraphs 3 and 6 of Art. 7-quater of Sardinia Regional Law no. 23 of 1985, as amended by the challenged provision, would allow a derogation from such requirements capable of finding application to all properties located in the regional territory.

In the first place, because the derogation would be applicable to buildings worthy of protection or to buildings located in historical centers – thus letters a) to c) of the challenged paragraph 3 – only when it is not possible to modify the original characteristics of the openings or create new ones.

In the second place, because the derogation sanctioned by letter d) of the same paragraph 3 for buildings "existing at the date of entry into force of the Decree of the Minister of Health of 5 July 1975," would be entirely in line with what was already recognized by administrative jurisprudence, according to which such decree would not be applicable to the aforementioned buildings.

As regards, instead, the hypothesis referred to in letter e) of the cited provision, which extends the derogation to buildings existing at the date of 24 May 2024, the regional defense reiterates that it is allowed "only in cases where it is not possible to modify the original characteristics of the openings or create new ones" and that in any case "[i]n the case of buildings open to the public, the derogation is applicable provided that, in the judgment expressed by the competent health authority, there is demonstrated, in relation to the intended use, to the number of occupants and to any other circumstance, the existence of suitable or equivalent hygienic-sanitary conditions of the property, also through the adoption of compensatory measures." The Region specifies, furthermore, that, as this Court would have clarified with judgment no. 124 of 2021, the limits referred to in M.D. of 5 July 1975 would be derogable in particular and limited circumstances, as in the case of attics, from which it should be concluded that such derogation could well be extended also to those buildings which, due to their architectural characteristics, cannot be modified, given that between the latter and the attics "the passage is short."

2.8.– The issues of constitutional legitimacy of Art. 14 of the challenged regional law should also be rejected.

In the first place, they would be inadmissible, as not supported by sufficient motivation.

Not only, in fact, would the appellant not have considered that Art. 11 of Sardinia Regional Law no. 23 of 1985, on which the challenged provision affected, was already in force and that the amendments made to it would not transpose only detail aspects of national legislation, but the State's findings, in their generic nature, would not identify "specific points of conflict with state discipline, if not the feared, abstract as it is indeterminate failure to transpose."

Moreover, in the regional defense's opinion, it would be totally unreasonable, as well as illegitimate for violation of the principle of differentiation and adequacy referred to in Art. 118 of the Constitution, the reading that the President of the Council of Ministers gives of Art. 23-ter, paragraph 1-quater, TUEd, based on which it would establish that urbanistically relevant categories, for which completely different parking provisions are provided, should be considered a priori of equal urban load, without allowing any evaluation of adjustment to territorial needs.

The respondent argues, then, that, by applying the discipline of Art. 23-ter, paragraph 1-bis, TUEd, the regional legislator would have "chosen to identify as urbanistically relevant the category of housing including relative services (regional law no. 23 of 1985, article 1, paragraph 1 letter a now in force), for which subsequent modifications occur in terms of 'horizontal' urban planning changes." The provision referred to in paragraph 1-quater of the cited Art. 23-ter of the Consolidated Act on Building, which would apply only to vertical intended use changes, according to which the change of intended use would not be subject to the obligation of finding further areas for general interest services referred to in M.D. no. 1444 of 1968, would then be "literally referred to the 'areas for general interest services' referred to in zone F (parts of the territory intended for equipment and facilities of general interest) of article 2 of M.D. 1444/1968 (element very different from the urban planning standards referred to in article 3) and to the 'mandatory minimum allocation of parking provided for by Law no. 1150 of 17 August 1942,' which are the parking spaces referred to in Law no. 122 of 24 March 1989 (so-called Tognoli Law), article 41-sexies of Law no. 1150/1942 and not also the parking spaces that in the planning phase the municipalities deemed necessary or those generated by sector regulations."

2.9.– Also the grievance of Art. 18 of the challenged regional law would be inadmissible and in any case unfounded.

In the respondent's opinion, the ground of challenge would limit itself to recalling in a generic and apodictic manner the arguments spent for the grievances of Art. 14, even if the two regulatory provisions are entirely different.

The regional defense, referring to the considerations made regarding the previous issues, regarding the scope of applicability of the cited Art. 23-ter, paragraph 1-quater, of the Consolidated Act on Building, deduces then that the cited Art. 18, for the purpose of orderly territorial management and within the scope of the primary legislative competence of the Region in matters of urban planning, would have provided – with a choice "more adherent to the principle of subsidiarity, differentiation and adequacy" – that even within the same urbanistically relevant category the change of destination may require further space for parking, to be evaluated from time to time during the drafting of the municipal urban planning instrument (general or detailed).

2.10.– The respondent asks that the challenge to Art. 15 of Sardinia Regional Law no. 18 of 2025 also be rejected.

The grievances would be in the first place inadmissible because not supported by sufficient and adequate motivation.

They would, in any case, be unfounded on the merits.

While confirming that the discipline referred to in Art. 36-bis TUEd would not have been transposed and that it would continue to be provided, in relation to works carried out in the absence of SCIA or in non-compliance with it, a procedural mechanism similar to that already provided for by Art. 37, paragraph 4, TUEd, repealed by Decree-Law no. 69 of 2024, as converted, the regional defense deduces that there would be no conflict with the principles of the cited decree-law, which would have provided, both for works legitimable through SCIA and for works subject to building permit, the certificate of compliance referred to in the cited Art. 36-bis, for "minor" abuses, and that referred to in Art. 36 TUEd, for "major" abuses.

The Sardinian legislator, in fact, would not have given the interested party the possibility of freely choosing between SCIA and building permit for the realization of building works provided for by Art. 22 of the Consolidated Act on Building and would therefore have established that the same interventions are subject to simple SCIA, "but the sanctions for works in violation of such regulation correspond to those provided [for] for violations connected to the lack/non-compliance with the building permit referred to in national legislation."

There would therefore be a substantial correspondence between the regional norm and the national one and the promoted issues should be declared unfounded.

2.11.– Lastly, the grievances relating to Art. 19 of the challenged regional law would be unfounded.

This article, in compliance with the principles of administrative simplification, would not have provided, in fact, for a certificate of compliance as a result of the realization of further works, but would have allowed the interested party to submit an amnesty request accompanied by a project for the removal of works that cannot be regularized. It would have, in other words, included in a single procedure the steps of the ordinary certificate of compliance on works not susceptible to such certification. The challenged norm would allow, therefore, to request, simultaneously with the aforementioned certificate, the permit for the relative removal, even if the amnesty title would be formed only following the inspection that verifies the actual removal of what is not regularizable. And, in the event that the proponent did not proceed with the removal of the parts of the work that are not regularizable within the rigorous terms assigned by the proceeding administration, the latter would immediately initiate procedures for the removal of the building abuse.

3.– In view of the public hearing, the President of the Council of Ministers filed a memorial, with which he replied to the respondent's deductions, insisting on the acceptance of the appeal.

Findings of Law

4.– With the appeal in the heading (reg. appeal no. 31 of 2025), the President of the Council of Ministers, represented and defended by the State Attorney General, has promoted, among others, issues of constitutional legitimacy of Arts. 2, 4, 6, 7, paragraph 1, letter d), 12, 14, 15, 18, paragraph 1, letter a), and 19 of Sardinia Regional Law no. 18 of 2025, alleging the violation of multiple constitutional and interposed parameters.

5.– The definition of the further issues promoted by the State with the same appeal remains reserved for a separate pronouncement.

6.– Preliminarily, it is necessary to examine the exception of inadmissibility due to the generic nature of the grounds, raised by the regional defense towards almost all the issues in question (exceptions, in fact, only the grievances concerning Arts. 4, in the part where it would derogate from the minimum protection distances of the railway line, and 19, of the challenged regional law).

According to the Region, the appellant would not have duly taken into account the primary legislative power of which it is the holder in the matter of "building and urban planning" by force of Art. 3, letter f), of the Special Statute; it would state in an apodictic and generic manner the conflict between the challenged regional norms and the interposed state discipline, qualified, in an equally generic and apodictic manner, as a fundamental norm of economic-social reform; nor would it have argued, with sufficiently clear and complete motivation, the deduced invasion of the exclusive state legislative competencies evoked in the various grounds of appeal.

Finally, the respondent excepts that the grievances proposed would be abstract, since the actual reasons placed at the basis of the appeal would not be adequately motivated, as well as the specific interest to promote the challenge.

6.1.– The referred general exceptions of inadmissibility must be rejected.

Except, in fact, what will be noted for some specific grievances, which effectively present the insufficiencies alleged by the Region, the State has duly taken into consideration the primary legislative power which, by force of the special statute, belongs to it and has deemed that, in practice, the limits of such power have been exceeded. The evaluation of the merits of this assumption then invests the merits of the issues, just as it relates to the merits the qualification in terms of fundamental norms of economic-social reform of the state provisions cited in the appeal (similarly, judgment no. 24 of 2022, point 2.2.2. of the Findings of Law).

The issues, moreover, exceed the minimum threshold of clarity required by constitutional jurisprudence and, therefore, allow the scrutiny of the merits, even if sometimes formulated in a synthetic manner or motivated by means of internal referral. Regarding this last profile, as clarified by this Court, the recalled argumentative technique is not, in itself, a reason for inadmissibility when the appellant, referring precisely to arguments already exposed in the previous pages of the appeal on grievances of similar nature (judgments no. 196 of 2025, point 7.4. of the Findings of Law; no. 90 of 2023, point 13.1.1. of the Findings of Law and no. 68 of 2011, point 3.2. of the Findings of Law), delineates a perfectly intelligible grievance.

7.– Still preliminarily, it must be recalled that Art. 3 of the Special Statute, in assigning the Autonomous Region of Sardinia primary legislative power in some matters, includes, at letter f), "building and urban planning."

The same Art. 3 specifies, however, that such power is subject, among other things, to respect for fundamental norms of economic-social reform established by the state legislator.

With reference to this category of norms, constitutional jurisprudence has constantly required "from special regions (and from the two autonomous provinces) respect for state legislative prescriptions of a general nature affecting matters subjected by the statutes to the regime of full or primary legislative competence" (judgment no. 229 of 2017, point 2.2. of the Findings of Law; similarly, more recently, judgments no. 22 of 2025, point 4 of the Findings of Law; no. 147, point 7.1.3. of the Findings of Law, and no. 90, point 6.2.2. of the Findings of Law, of 2023, and no. 24 of 2022 point 3.1. of the Findings of Law). The state legislator retains, therefore, the power to bind the primary legislative power of the aforementioned entities with special autonomy.

Fundamental norms of economic-social reform are those characterized by the "''[...] salient characteristics' [...] identified 'in the reformist content and in the pertinence to sectors or goods of economic-social life of significant importance' (judgment no. 24 of 2022). They, on the other hand, ''respond overall to a unitary interest and require, therefore, an implementation throughout the national territory' (judgment no. 198 of 2018)' (judgment no. 90 of 2023)" (thus judgment no. 22 of 2025, point 4 of the Findings of Law), together with "the close relationship of instrumentality" that the challenged regional provisions entertain with the good or with the interests of constitutional rank involved in the discipline (judgment no. 198 of 2018, point 6.2.2. of the Findings of Law).

Regarding the matter of building, on several occasions this Court, while clarifying that the qualification in question "''cannot be attributed, immediately and indistinctly, to all the provisions''" of the TUEd, "''but must be evaluated from time to time, in light of their ratio' (judgment no. 198 of 2018)" (judgment no. 22 of 2025, point 4 of the Findings of Law), has qualified in this sense several of its provisions and essentially those concerning enabling titles and the discipline of the certificate of compliance (judgments no. 147, point 7.1.3. of the Findings of Law; and no. 90, point 6.2.2. of the Findings of Law, of 2023 and no. 24 of 2022, point 9.3.1. of the Findings of Law).

8.– Lastly, it must be specified that, for reasons of clarity and simplicity of exposition, this Court, availing itself of the power to determine the order of issues to be addressed (among many, judgments no. 196 of 2025, point 7.6. of the Findings of Law, and no. 192 of 2024, point 13.2. of the Findings of Law), will not follow that of the grievances proposed by the appeal.

9.– The State, in the first part of the first ground of appeal, challenges first of all Art. 2 of Sardinia Regional Law no. 18 of 2025, in the part where it introduces Art. 2-bis, paragraph 3, into Sardinia Regional Law no. 23 of 1985, which establishes that "[f]or the purposes of a correct application of the definitions referred to in paragraph 1, the realization of new volume in an existing construction is considered building renovation if it occurs within the existing outline and new construction otherwise."

The appellant alleges, in the first place, the violation of Arts. 3 of the Special Statute and 117, second paragraph, letter s), of the Constitution, in relation to Arts. 3, paragraph 1, letter d), and 10, paragraph 1, letter a), TUEd, in that, by affecting the identification of building intervention categories and, in particular, qualifying the volume expansion "within the outline" as "building renovation," it would conflict with the referenced state provisions, which constitute fundamental norms of economic-social reform. The Sardinian legislator, in fact, would not only have defined building renovation differently, but would also have affected its enabling regime, building renovation interventions with volume increase being executable by means of SCIA and not only with a building permit.

The violation of Art. 117, second paragraph, letter m), of the Constitution is also alleged, in that "The potential identification, by the regional norm, of a different building title compared to that provided for by the TUE could imply transformations of the territory so significant as to affect, in a disproportionate and unreasonable manner, the essential levels of service of civil and social rights that must be guaranteed uniformly throughout the national territory."

9.1.– The issue promoted with reference to Art. 3 of the Special Statute is founded.

9.1.1.– It is preliminarily appropriate to recall, for what is relevant in today's proceeding, the state discipline of building renovation.

Art. 3, paragraph 1, letter d), Consolidated Act on Building, establishes that "building renovation" interventions are those "aimed at transforming building organisms through a systematic set of works that can lead to a building organism in whole or in part different from the previous one. Such interventions include the restoration or replacement of some constituent elements of the building, the elimination, modification and insertion of new elements and systems. Within the scope of building renovation interventions are also included demolition and reconstruction interventions of existing buildings with different outline, elevations, footprint and planivolumetric and typological characteristics, with the necessary innovations for adaptation to anti-seismic regulations, for the application of accessibility regulations, for the installation of technological systems and for energy efficiency. The intervention can also provide, in the sole cases expressly provided for by current legislation or municipal urban planning instruments, volumetric increases also to promote urban regeneration interventions. Also constituting building renovation are interventions aimed at restoring buildings, or parts of them, which may have collapsed or been demolished, through their reconstruction, provided it is possible to ascertain the pre-existing consistency. It remains firm that, with reference to properties subject to protection pursuant to the Code of Cultural Heritage and Landscape, referred to in Legislative Decree no. 42 of 22 January 2004, with the exception of buildings located in areas protected pursuant to articles 136, paragraph 1, letters c) and d), and 142 of the same code, as well as, without prejudice to the provisions of legislation and urban planning instruments, to those located in homogeneous zones A referred to in the Decree of the Minister of Public Works of 2 April 1968, no. 1444, or in zones assimilable to these based on regional legislation and municipal urban planning plans, in consolidated historical centers and nuclei and in further areas of particular historical and architectural value, demolition and reconstruction interventions and restoration interventions of collapsed or demolished buildings constitute building renovation interventions only where outline, elevations, footprint and planivolumetric and typological characteristics of the pre-existing building are maintained and no volumetric increases are provided for."

As can be seen, the cited provision, in the first place, includes in renovation interventions aimed at the transformation of building organisms through a systematic set of works that can lead to a building organism in whole or in part different from the previous one ("basic" renovation). Such interventions include the restoration or replacement of some constituent elements of the building, the elimination, modification and insertion of new elements and systems.

Alongside this type is another one, so-called demo-reconstruction, in which are included demolition and reconstruction interventions that modify outline, elevations, footprint and planivolumetric and typological characteristics, as well as, in the sole cases expressly provided for by current legislation or municipal urban planning instruments, with "volumetric increases also to promote urban regeneration interventions."

Finally, also falling under renovation are interventions aimed at restoring buildings, or parts of them, which may have collapsed or been demolished, through their reconstruction, provided it is possible to ascertain the pre-existing consistency (restoration renovation).

While for "basic" renovation the state provision does not refer to any changes in volume and/or outline, for the other two categories it normally admits (expressly for demo-reconstruction and a contrario – because there are expressly provided cases in which this is not allowed – for "restoration renovation") the modification of the outline, elevations, footprint and planivolumetric and typological characteristics. Furthermore, it is reiterated, in the cases expressly provided for by current legislation or municipal urban planning instruments, demo-reconstruction can include volumetric increases also to promote urban regeneration interventions.

However, for properties subject to constraints or for those located in historical centers and further areas of particular historical and architectural value, demo-reconstruction and restoration renovation interventions fall under the category of renovation only if they maintain unaltered outline, elevations, footprint and planivolumetric and typological characteristics of the pre-existing building and do not entail "volumetric increases."

9.1.2.– In order to frame today's issue of constitutional legitimacy it is also appropriate to recall that the current – complex – extension of the notion of "renovation" constitutes the result of various regulatory amendments that have affected Art. 3 TUEd. Even if, on one hand, they have determined a progressive distance, for demo-reconstruction and restoration renovation interventions, from the original obligation of faithful reconstruction, on the other hand, it continues to be considered necessary that there exists a "nexus of continuity" between the pre-existing building and that resulting from the intervention, on the assumption that only interventions that are functional to the reuse of the previous volume and that do not entail further transformation of the territory compared to that already determined by the pre-existing property can qualify as building renovation (Council of State, Second Section, judgment no. 8542 of 4 November 2025).

In light of the referenced regulatory and jurisprudential framework, it is evident that, while volumetric increases are by no means excluded within the building renovation category, they are expressly disciplined and subjected to limits and conditions.

On the basis of what precedes, the challenged regional norm, by automatically including among building renovation interventions those that maintain the outline, but determine a volume increase, is not coherent with the cited state discipline.

The Sardinian regional legislator, in fact, generically leads back to the notion of renovation any volumetric expansion, to the sole condition that it occurs within the outline. A clear misalignment with the cited Art. 3, paragraph 1, letter d), ensues, which is undoubtedly attributable to the fundamental norms of economic-social reform, since it concerns an area, that of the qualification of building interventions, of certain economic-social significance, which therefore demands uniform implementation throughout the national territory.

9.2.– To this – which constitutes in itself a ground of constitutional illegitimacy of the challenged regional norm – must be added that, as the President of the Council of Ministers correctly notes, the challenged provision also conflicts with the discipline of enabling titles.

From the qualification of the intervention as "building renovation" or as "new construction" depends, in fact, the identification of the building title necessary to legitimize it, which, normally, for renovation is the SCIA (Art. 22, paragraph 1, letter c), TUEd) and for "new construction" is the building permit (Art. 10, paragraph 1, letter a) of the same consolidated act).

Regardless of the delimitation of the notion of renovation referred to in the last sentence of Art. 3, paragraph 1, letter d), the Consolidated Act on Building identifies, in fact, in Art. 10, paragraph 1, letter c), some cases of "renovation" – so-called "heavy" – which it subjects to a building permit (and of which, in Art. 23, it allows "As an alternative" the realization by means of SCIA: in practice, "Super-SCIA") and leads back to it "interventions [...] that lead to a building organism in whole or in part different from the previous one, in cases where they also entail modifications of the total volume of the buildings or which, limited to properties included in homogeneous zones A, entail changes of intended use, as well as interventions that entail modifications of the outline or the total volume of the buildings or of the elevations of properties subject to protection pursuant to the Code of Cultural Heritage and Landscape referred to in Legislative Decree no. 42 of 22 January 2004, and, furthermore, building renovation interventions that entail the demolition and reconstruction of buildings located in areas protected pursuant to articles 136, paragraph 1, letters c) and d), and 142 of the same code referred to in Legislative Decree no. 42 of 22 January 2004, or the restoration of buildings, collapsed or demolished, located in the same areas, in both cases where modifications of the outline or elevations or footprint or planivolumetric and typological characteristics of the pre-existing building are provided for or volumetric increases are provided for."

It can be deduced, therefore, that, beyond the fact that the intervention can be included in the definition of new construction or in that of renovation, the volume increase subjects it to the building permit (or to the SCIA as an alternative to it).

Having premised this, the challenged regional provision illegitimately affects the regime of enabling titles, in that building renovation interventions that determine volume increases, but not outline changes, in the Sardinian regional legal system are subjected to simple SCIA and not to the building permit or to the SCIA as an alternative to it according to the conditions and limits established by the Consolidated Act on Building.

9.3.– The respondent, on the point, defends itself by maintaining that, regardless of inclusion in one or the other category (building renovation or new construction), both types of interventions would be subjected by regional legislation to the building permit.

The assumption is not founded.

If it is true, in fact, that Art. 3 of Sardinia Regional Law no. 23 of 1985 – which is the provision to which reference is made – subjects both building renovation and new construction to the building permit, it must equally be considered that Art. 10-bis, paragraph 1, letter f), of the same regional law subjects to SCIA precisely building interventions that do not entail modification of the "outline of the existing or pre-existing building organism."

In other words, based on the combined provisions of Arts. 2-bis, paragraph 3, and 10-bis, paragraph 1, letter f), of Sardinia Regional Law no. 23 of 1985, building renovation interventions with maintenance of outline and volume increase are subjected to SCIA (ordinary) and not to the building permit.

If, therefore, one considers the overall framework of the aforementioned regional law, the challenged provision, in the automatic and general ascription of volumetric increases within the outline within the building renovation category, is not compliant with Art. 10, paragraph 1, letter c), TUEd, which for building renovation interventions entailing volume increase requires instead the provision title.

9.4.– Stated the nature of fundamental norm of economic-social reform of the cited state provision, also for such profile the challenged norm violates the general limit to the exercise of the primary legislative power of the Autonomous Region of Sardinia in the matter of building and urban planning.

The constitutional illegitimacy of Art. 2 of Sardinia Regional Law no. 18 of 2025, in the part where it introduces Art. 2-bis, paragraph 3, into Sardinia Regional Law no. 23 of 1985, must therefore be declared, for violation of Art. 3 of the Special Statute.

The other grievances remain absorbed.

10.– The State challenges then a series of regional provisions (specified below) regarding the notions of total and partial non-compliance and the discipline of the relative titles of legitimation (original and "amnesty").

10.1.– At the examination of the relative issues it is appropriate to premise a brief framework of the discipline of the TUEd invoked by the State as an interposed parameter.

10.1.1.– Art. 31, paragraph 1, of the cited consolidated act defines interventions carried out in total non-compliance with the building permit as "those that entail the realization of a building organism entirely different for typological, planivolumetric or utilization characteristics from that object of the permit itself, or the execution of building volumes beyond the limits indicated in the project and such as to constitute a building organism or part of it with specific relevance and autonomously usable."

Art. 32, paragraph 1, of the same consolidated act, in delegating to regions the identification of variations to the approved project that, while not integrating a total non-compliance, are qualifiable as "essential," specifies that "essentiality recurs [in any case] exclusively when one or more of the following conditions is verified:

a) change of intended use that implies variation of the standards provided for by the ministerial decree of 2 April 1968, published in the Official Gazette no. 97 of 16 April 1968;

b) consistent increase in cubage or roof surface to be evaluated in relation to the approved project;

c) substantial modifications of urban-building parameters of the approved project or of the location of the building in the area of relevance;

d) change of the characteristics of the approved building intervention;

e) violation of current regulations in the matter of anti-seismic building, when it does not pertain to procedural facts."

It is also clarified, in paragraph 2 of the same article, that "Variations that affect the entity of accessory cubages, technical volumes and internal distribution of individual housing units cannot be considered essential" and, in paragraph 3, that the interventions referred to in the list (i.e., those considered by paragraph 1) if they are "carried out on properties subject to historical, artistic, architectural, archaeological, landscape, environmental and hydrogeological constraints, as well as on properties falling on parks or in national and regional protected areas, are considered in total non-compliance with the permit, for the purposes and effects of articles 31 and 44."

The TUEd does not instead define partial non-compliance, which represents a residual category compared to those of total non-compliance and essential variation.

On the point, administrative jurisprudence has clarified that "The notion of partial non-compliance [...] presupposes that a certain building intervention, even if contemplated by the authorization title issued by the administrative authority, is realized according to methods different from those provided for and authorized at the design level, when the modifications affect particular and non-essential elements of the construction and materialize in qualitative and quantitative divergences not affecting the essential structures of the work; while one is in the presence of total non-compliance of the artifact or of essential variations, sanctionable with demolition, when the works concern a work different from that provided for by the concession act for conformation, structuring, destination, location" (Council of State, Second Section, judgment no. 906 of 29 January 2024).

Even if it does not offer a definition of partial non-compliance, the TUEd disciplines its effects, establishing – for what concerns us here – that "Interventions and works carried out in partial non-compliance with the building permit are removed or demolished at the expense and care of those responsible for the abuse" (Art. 34, paragraph 1) and that, if the restoration cannot take place without prejudice to the part carried out in compliance, a pecuniary sanction is applied (Art. 34, paragraph 2).

10.1.2.– The discipline of total non-compliance, essential variations and partial non-compliance is then connected to that of the relative amnesties, dictated by Arts. 36 and 36-bis TUEd, as respectively amended and introduced by Decree-Law no. 69 of 2024, as converted.

Art. 36 ("Certificate of compliance in the hypotheses of absence of title or total non-compliance") establishes, in fact, in paragraph 1, that "In case of interventions carried out in the absence of a building permit or in total non-compliance in the hypotheses referred to in Article 31 or in the absence of certified notification of commencement of activity in the hypotheses referred to in Article 23, paragraph 01 [SCIA alternative to the permit], or in total non-compliance with it, until the expiry of the terms referred to in articles 31, paragraph 3, 33, paragraph 1, and in any case until the imposition of administrative sanctions, the person responsible for the abuse, or the current owner of the property, can obtain the permit in amnesty if the intervention results in compliance with urban planning and building discipline both at the time of its realization, and at the time of the submission of the application."

Provision is therefore made for such a rigorous method of regularization (which requires the described "double compliance" with pre-existing and current urban planning and building norms) for the most radical abuses: interventions subject to building permit (or to the SCIA alternative to it) totally devoid of the aforementioned title.

In these cases, the institution of the certificate of compliance allows to regularize only interventions that are only formally illegitimate, as they are compliant in substance both with urban planning regulations and with building ones, not only at the time of the relative request, but also at the time they were executed. The necessity of double compliance – as clarified most recently by judgment no. 125 of 2024, point 3.1. of the Findings of Law – not only represents a fundamental principle of the matter, but also constitutes a fundamental norm of economic-social reform.

10.1.3.– Decree-Law no. 69 of 2024, as converted, in restricting the scope of application of the certificate of "double compliance" to the aforementioned abuses of greater severity, has delineated, in the new Art. 36-bis ("Certificate of compliance in the hypotheses of partial non-compliance and essential variations"), a regime of "simplified double compliance" for abuses considered less relevant, providing, in paragraph 1, that "In case of interventions carried out in partial non-compliance with the building permit or with the certified notification of commencement of activity in the hypotheses referred to in article 34 [SCIA alternative to the permit] or in the absence or non-compliance with the certified notification of commencement of activity in the hypotheses referred to in article 37, until the expiry of the terms referred to in article 34, paragraph 1, and in any case until the imposition of administrative sanctions, the person responsible for the abuse or the current owner of the property can obtain the building permit and submit the certified notification of commencement of activity in amnesty if the intervention results in compliance with the urban planning discipline in force at the time of the submission of the application, as well as with the requirements prescribed by the building discipline in force at the time of the realization. The provisions of this article also apply to essential variations referred to in article 32."

Therefore, in cases of interventions carried out in partial non-compliance or essential variation from the building permit (or from the SCIA alternative to it) or in absence or non-compliance with the ordinary SCIA, it is possible to also regularize abusive works that result in compliance only with the urban planning discipline in force at the time of the submission of the application and with the requirements prescribed by the building discipline in force at the time of their realization.

Having reconstructed the relevant state discipline, one can pass to the examination of the connected issues of constitutional legitimacy.

10.2.– With the fifth ground of appeal, the State challenges Art. 6 of Sardinia Regional Law no. 18 of 2025, in the part where it modifies Art. 4, paragraph 2, of Sardinia Regional Law no. 23 of 1985.

The new Art. 4, paragraph 2, provides that "are considered in total non-compliance with the enabling title the execution of building volumes or the realization of covered surfaces beyond 30 percent, for buildings existing at the date of 24 May 2024, and 20 percent, in all other cases, of the limits indicated in the project, as well as modifications greater than 50 percent of the distances from buildings, from the boundaries of the lot and from the roads indicated in the project, or reductions of any entity that determine distances lower than the minimums provided for by current provisions. Regardless of the provisions referred to in the first sentence, total non-compliance is considered the modification of the location of the building within the relevant urban plot when there is no overlapping of the footprint on the ground of the authorized building and the realized one."

In the opinion of the President of the Council of Ministers, the challenged regional regulation, in introducing a notion of total non-compliance in quantitative terms, would conflict, in the first place, with what is prescribed by Art. 31, paragraph 1, TUEd, which defines the cases of total non-compliance with the building permit in exclusively qualitative terms, and would also violate Art. 32 of the cited consolidated act, because the operation would also have effects on the delimitation of essential variations.

Moreover, the amended Art. 4, paragraph 2, in affecting the identification of the type of building violation relevant from time to time, would allow the regularization of building non-compliances based on enabling titles or procedures different from those indicated by state norms. In such a way the regional legislator would have interfered with the choices made on the side of amnesty by the state legislator, who refers interventions constituting essential variations to the regime referred to in Art. 36-bis TUEd and those carried out in total non-compliance to Art. 36 of the cited consolidated act.

Therefore, the violation of Art. 3 of the Special Statute would result, in the first place, and, in the second place, the regional legislator having also affected the identification of the cases of crime, "determining a substantial modification of the criminal law profiles connected to the realization of interventions in the absence or total non-compliance with the building title," the exclusive state legislative competence in the matter of criminal law, referred to in Art. 117, second paragraph, letter l), of the Constitution, would also be harmed.

10.2.1.– The issue promoted with reference to Art. 3 of the Special Statute is founded.

Based on the general reconstruction carried out, the discrepancy between the notion of total non-compliance established by the State and that delineated by the Sardinian legislator is evident, and this, as the appellant correctly highlights, also affects the discipline of amnesty, since it influences the application of Art. 36 TUEd (where, for what has been exposed, stricter rules are dictated, for such purposes, in case of absence or total non-compliance with the permit or the alternative SCIA), which, as the already recalled constitutional jurisprudence has clarified, must be considered a fundamental norm of economic-social reform.

This latter qualification must be recognized also to Arts. 31 and 32 of the same consolidated act, given their reformist content, their pertinence to sectors or goods of economic-social life of significant importance and the consequent necessity that the interests disciplined by them receive homogeneous implementation throughout the national territory.

The argument spent by the regional defense in support of the legitimacy of the challenged provision, according to which, paragraph 1 of Art. 4 of Sardinia Regional Law no. 23 of 1985 carrying a notion of total non-compliance identical to the state one, the challenged paragraph 2 would be integrated with state discipline, which would continue to find application, does not have merit. Such defensive thesis finds, in fact, denial in the very formula adopted by the cited paragraph 2, i.e., "[f]or the purposes of the application of the provisions referred to in paragraph 1 are considered in total non-compliance," which resolves within the quantitative limits provided by the same the general notion referred to in the cited paragraph 1.

10.2.2.– The constitutional illegitimacy of Art. 6 of Sardinia Regional Law no. 18 of 2025 must therefore be declared, in the part where it modifies the cited Art. 4, paragraph 2.

The further grievances remain absorbed.

10.3.– Art. 7, paragraph 1, letter d), of the same challenged regional law is also challenged, with the sixth ground of appeal, which introduces paragraph 1-bis into Art. 5 in the cited regional law no. 23 of 1985.

The cited paragraph 1-bis identifies as partial non-compliance with respect to the project those that do not reach the limits set for essential variations and, in the case of modifications of the location of the building within the relevant urban plot determined following rotation on any axis or translation, variations greater than 50 percent.

The State laments that it would be precluded for the regional legislator to identify the notion of "partial non-compliance" by indicating quantitative limits, which could have the effect of circumscribing the scope of the abusive conduct, with effects also on the side of the criminal sanction.

In other words, in the appellant's opinion, the Sardinian legislator, by inserting into the definition of essential variation cases of partial non-compliance identified in quantitative terms, would have exceeded its primary legislative competence, because it would have introduced a discipline incompatible with that expressed by Arts. 31, paragraph 1, and 32, paragraph 1, TUEd, which would qualify as norms of economic-social reform.

Therefore, Art. 3 of the Special Statute and, for the same reasons, Art. 117, second paragraph, letter s), of the Constitution, would be violated, as well as the exclusive state legislative competence in the matter of criminal law, referred to in letter l) of the cited constitutional provision, in that the challenged regional norm would go to circumscribe the scope of the abusive conduct, as well as its effects, also on the side of the criminal sanction.

10.3.1.– Before passing to the examination of the promoted issues it is first of all necessary to recall the definition of essential variations contained in paragraph 1 of Art. 5 of Sardinia Regional Law no. 23 of 1985, according to which fall into such category the variations "which, realized without respecting the provisions referred to in article 7-ter, have determined at least one of the following conditions:

a) change of intended use incompatible with the zone destination or which implies variations in increase of the limits and ratios provided for by the Decree of the Councilor for Local Authorities, Finance and Urban Planning no. 2266/U of 20 June 1983 (Regulation of limits and ratios relating to the formation of new urban planning instruments and the revision of existing ones in the Municipalities of Sardinia) unless the interested party cedes further areas to integrate the share provided for in relation to the changed intended use;

b) increase greater than 20 percent of the cubage or covered surface, for buildings existing at the date of 24 May 2024, and 10 percent, in all other cases;

c) reduction in measure greater than 20 percent, for buildings existing at the date of 24 May 2024, and 10 percent, in all other cases, of one of the following parameters:

1) distance from other buildings;

2) distance from the boundaries of the lot;

3) distance from roads;

d) regardless of the provisions referred to in letters a), b) and c), modification of the location of the building within the relevant urban plot determined following rotation on any axis or translation, when the overlapping of the footprint on the ground of the authorized building and the realized one is less than 50 percent."

To resolve the issue of constitutional legitimacy now under examination it is also necessary to recall that, as this Court has clarified, even if by express provision of Art. 32, paragraph 1, TUEd regions are competent to identify interventions that constitute essential variations, regulatory legislation that denies "in a general way the consistency of essential variation to modifications that remain below a certain percentage threshold" is not compatible with the cited state provision, given that even modifications below the eventual percentage thresholds identified by regional legislators can determine the substantial diversity of the work compared to that object of the enabling title (judgment no. 119 of 2024, point 23.3. of the Findings of Law).

Therefore, regional legislation on essential variations (even if attributable to the primary legislative competence of regions with special statutes, given the already recalled character of fundamental norm of economic-social reform of the cited Art. 32, paragraph 1) must be interpreted in the sense that exceeding the eventual quantitative limits provided determines certainly an essential variation, but not also that, a contrario, below such limits the essentiality of the variation can be automatically excluded, it having to be always possible, for the interpreter, to evaluate whether the intervention determines the substantial diversity compared to the authorized intervention.

10.3.2.– Having premised this, the issue promoted with reference to Art. 3 of the Special Statute is founded.

The Region, in fact, establishing that the non-compliance that does not reach the quantitative limits set to determine the essentiality of the variations is to be considered (where it does not fall into "Constructive tolerances": Art. 34-bis TUEd) as partial non-compliance, determines a priori the exclusion from essentiality of those variations which, due to conformation, structuring, destination or location, make a work substantially different from that provided for by the enabling title.

In other words, the reason for constitutional illegitimacy lies in the exclusion ex lege, i.e., regardless of any concrete appreciation regarding their actual incidence, of those building interventions that do not reach the indicated quantitative threshold, but which however, through an appreciation in practice, configure essential variations.

The definition operation performed by the Sardinian legislator conflicts not only with what is established by the cited Art. 32, paragraph 1, TUEd, but has also consequences on the regime to which interventions that did not reach the aforementioned quantitative thresholds would be subjected.

If it is true, in fact, that following the amendments introduced by Decree-Law no. 69 of 2024, as converted, both partial non-compliance and essential variations are subjected to the regime of the simplified certificate of compliance referred to in Art. 36-bis TUEd, and that therefore the regional intervention has no consequences in such an area, on the other hand, it is also true that essential variations, on one hand, are subject to the issuance of a building permit entirely new and autonomous, "since characterized by incompatibility with the original building project based on parameters derivable, by way of example, from Art. 32 TUEd [...] (Council of State, Sixth Section, judgments no. 4279 of 3 June 2021 and no. 891 of 6 February 2019)" (judgment no. 119 of 2024, point 23.1.1. of the Findings of Law), and, on the other, continue to be subjected to the stricter repressive regime – proper to the absence of title or total non-compliance with it – of the obligation of demolition or removal (Art. 31, paragraph 2, TUEd), under penalty of free acquisition to the municipality's heritage of the asset and of the footprint area, and without the possibility of regularizing the abuse, where its removal would cause prejudice to the part executed in compliance, with the payment of a pecuniary sanction (i.e., the so-called fiscalization of the abuse, provided for partial non-compliance).

The considerations made so far also destine from the roots of foundation the argument, spent by the respondent, according to which regions, being able – by provision of the same Art. 32, paragraph 1, TUEd – to define, also quantitatively, essential variations from the approved project, should, implicitly and necessarily, be able to establish also the limit of partial non-compliance.

10.3.3.– The constitutional illegitimacy of Art. 7, paragraph 1, letter d), of Sardinia Regional Law no. 18 of 2025 must therefore be declared, for violation of Art. 3 of the Special Statute, with absorption of the other grievances.

10.4.– The President of the Council of Ministers, with the tenth ground of appeal, also alleges the constitutional illegitimacy of Art. 15 of Sardinia Regional Law no. 18 of 2025, for violation of Arts. 3 of the Special Statute and 117, second paragraph, letter s), of the Constitution, in relation to Art. 36-bis TUEd.

The appellant laments that following the amendments made by the challenged Art. 15, Art. 14 of Sardinia Regional Law no. 23 of 1985, which disciplines works carried out in the absence of SCIA (ordinary) or in non-compliance with it, would continue illegitimately to provide for a "form of amnesty conditional on the payment of a pecuniary sanction of 500 euros and the payment of construction fees where due, according to a procedural mechanism similar to that already provided for by [repealed] article 37, paragraph 4, of the TUE," diverging from what is provided for by Art. 36-bis of the same consolidated act, evoked as an interposed parameter.

The issues must be declared inadmissible, in that the motivation in support of the challenge is lacking and merely assertive.

The appeal has not first of all taken adequately and exactly into consideration the regulatory scope neither of Art. 14 of Sardinia Regional Law no. 23 of 1985, as modified by the challenged Art. 15, nor of Art. 36-bis TUEd and it does not result adequately illustrated in what way the challenged Art. 15, and therefore the discipline introduced by the latter, conflicts with the evoked interposed parameter.

As remarked by this Court, for the motivation requirement requested in proceedings in the principal instance to be adequately met, it is not sufficient the mere indication of norms to be compared, but it is necessary to also enumerate their content, and demonstrate, with clear, complete and sufficiently articulated arguments, the conflict between the two disciplines (among the most recent, judgments no. 196 of 2025, point 6.7.1. of the Findings of Law and no. 89 of 2024, point 4.1.3. of the Findings of Law).

It is not then certainly suitable to make overcome the found defect of admissibility the argument that Art. 14 of Sardinia Regional Law no. 23 of 1985, as resulting from the amendments of the challenged Art. 15, would continue to provide for a mechanism similar to that of the cited Art. 37, paragraph 4, TUEd, no longer in force.

As the basis of the statement, the appeal limits itself in fact to recalling the provision referred to in Art. 14, paragraph 2, of Sardinia Regional Law no. 23 of 1985, which simply provides that "[i]n the same cases referred to in paragraph 1, before the assessment of the execution of works in the absence of SCIA or in non-compliance with it, a communication of missing SCIA accompanied by all the documents provided for by article 10-bis, paragraph 2, can be transmitted; in such case, the amnesty is conditional on the payment of a pecuniary sanction of 500 euros and the payment of construction fees where due. Without prejudice to the application of article 7-ter, paragraph 6, the SCIA, spontaneously performed when the intervention is in the course of execution, entails the application of a sanction of 250 euros."

Now, the challenged norm, therefore, does not reproduce, neither directly, nor indirectly, the discipline of the repealed Art. 37, paragraph 4, TUEd, nor is the latter in any form recalled in the entire structure of the cited Art. 14. It does not result clear, therefore, also for such reason, under which profile the challenged regional discipline would diverge from what is prescribed by the cited Art. 36-bis.

One must therefore conclude in the sense of the inadmissibility of the issues of constitutional legitimacy of the challenged Art. 15, promoted with reference to Arts. 3 of the Special Statute and 117, second paragraph, letter s), of the Constitution.

10.5.– Furthermore, Art. 19 of Sardinia Regional Law no. 18 of 2025 is challenged, with the eleventh ground of appeal, in the part where it modifies Art. 16, paragraph 3, of Sardinia Regional Law no. 23 of 1985.

The cited Art. 16, in the new paragraph 3, object of grievance, provides that "[t]he application for certificate of compliance [in the hypotheses of absence of title or total non-compliance] can be accompanied by the project of the works necessary to ensure compliance with compliance conditions. Such works concern solely the interventions necessary for the elimination of parts or incongruous elements and in any case not ascertainable, and interventions aimed at the modification of the existing to bring it back to the typological-architectural solutions provided for by the municipal urban planning instruments in force at the time of the application for certificate of compliance. No new construction is allowed."

The State alleges the violation of Art. 3 of the Special Statute, for conflict with Art. 36 TUEd, a fundamental norm of economic-social reform.

The violation of Art. 117, second paragraph, letter l), of the Constitution would also result, in the matter of criminal law, in that, providing for a possibility of amnesty not contemplated by state legislation, it would expand the scope of the extinctive effects of the crime.

10.5.1.– On the merits, the issue promoted with reference to Art. 3 of the Special Statute is founded.

The appellant's perspective is correct, from the moment that the cited Art. 36 Consolidated Act on Building, requiring double compliance with the urban planning and building discipline in force both at the time of the realization of the intervention and at the time of the submission of the application, does not offer the applicant the possibility of carrying out interventions aimed at determining such conditions.

Such possibility was indeed introduced by the new Art. 36-bis, paragraph 2, TUEd, but only for less serious abuses (supra, points 10.1.2. and 10.1.3.).

The Sardinian legislator has, therefore, overstepped the limits of its primary legislative competence in the matter of building and urban planning.

As this Court has already had the opportunity to clarify, in fact, it is the task of the State "both in the office of defining the fundamental principles of the matter 'governance of the territory', and in the office of adopting the fundamental norms of economic-social reform" to determine, "in protection of the effectiveness of urban planning and building discipline throughout the national territory," the prerequisites, conditions and limits of the discipline of amnesty for building abuses (judgment no. 125 of 2024, point 3.4. of the Findings of Law).

10.5.2.– The constitutional illegitimacy of Art. 19 of Sardinia Regional Law no. 18 of 2025, in the part where it modifies Art. 16, paragraph 3, of Sardinia Regional Law no. 23 of 1985, for violation of Art. 3 of the Special Statute, must therefore be declared.

The further grievances are absorbed.

11.– In the second part of the seventh ground of appeal, the State challenges Art. 12 of Sardinia Regional Law no. 18 of 2025, where it modifies Art. 7-quater, paragraphs 3, letters d) and e), and 6, of the cited Sardinia Regional Law no. 23 of 1985, for violation of Art. 32 of the Constitution.

The appellant deduces that Art. 7-quater, paragraphs 3, letters d) and e), and 6, would be constitutionally illegitimate in the part where it admits, for the purposes of habitability, generalized derogations from air-lighting requirements referred to in M.D. of 5 July 1975, concerning properties existing at the date of entry into force of the cited ministerial decree (letter d) and those subsequent to such date and pre-existing to that of 24 May 2024 (letter e).

11.1.– The issue is founded.

11.2.– As regards air-lighting requirements, Art. 5 of the recalled M.D. prescribes for all "premises of the housing units," with the exception of those intended for hygienic services, disengagements, corridors, stairwells and closets, a "direct natural lighting, adequate to the intended use" (paragraph 1), and establishes the size of the window and the openable window surface (paragraph 2).

It is also necessary to recall that the prescriptions of the cited ministerial decree on air-lighting requirements, of which the State has lamented the violation (as well as those on minimum heights of residential premises, as integrated by the inter-ministerial decree of 26 June 2015, regarding "Application of calculation methodologies of energy performance and definition of prescriptions and minimum requirements of buildings"), have a technical nature and form a single body with what is provided by Art. 218 of Royal Decree no. 1265 of 27 July 1934 (Approval of the consolidated act of sanitary laws), which delegates to the competent Minister the power to issue "maximum instructions," so that the "local health and hygiene regulations" ensure, among other things, that "in dwellings: a) there is no defect of air and light."

The recalled prescriptions, linked by an evident nexus to primary legislation and directed to specify it, on the technical side, the general precepts, aim, in fact, to safeguard the healthiness and habitability of environments and are therefore inseparably connected to the implementation of Art. 32 of the Constitution.

As already clarified by this Court, "The prescriptions regarding the internal height of buildings, like air-lighting parameters, pursue the essential purpose of conforming building activity and, in such area, prepare measures aimed also at ensuring the right to health in the context of housing, a space of vital importance in the existence of every person" (judgment no. 124 of 2021, point 6.4.1. of the Findings of Law and, in conformity, judgment no. 119 of 2024, point 16 of the Findings of Law).

Therefore, the discipline of hygienic-sanitary requirements – specifically, of air-lighting – referred to in the cited ministerial decree must find homogeneous application throughout the national territory.

The necessity of the generalized respect of the referenced state prescriptions is indeed confirmed by Art. 10, paragraph 2, of Decree-Law no. 76 of 6 July 2020 (Urgent measures for simplification and digital innovation), converted, with amendments, into Law no. 120 of 11 September 2020, which provides that "In the meantime of the approval of the decree of the Minister of Health referred to in article 20, paragraph 1-bis, of the Presidential Decree no. 380 of 6 June 2001, the provisions referred to in the decree of the Minister of Health of 5 July 1975, published in the Official Gazette no. 190 of 18 July 1975, are interpreted in the sense that the requirements relating to minimum height and the hygienic-sanitary requirements of residential premises provided therein are not considered referred to properties that were realized before the date of entry into force of the same decree and that are located in zones A or B, referred to in the ministerial decree of 2 April 1968, no. 1444, or in zones assimilable to these, based on regional legislation and municipal urban planning plans. For the purposes of the submission and issuance of enabling titles for the recovery and building qualification of the same properties and for the certified notification of their habitability, reference is made to the legitimately pre-existing dimensions."

Therefore, in order to be able to exempt residential premises from the obligation of compliance with the requirements prescribed by the cited M.D. 5 July 1975, it is not sufficient – as the respondent maintains – that the property was realized prior to the date of entry into force of such decree, but the concurrence of the further and more stringent condition is required that the same property is located in zones A or B referred to in M.D. no. 1444 of 1968, or in zones assimilable to these.

Furthermore, the circumstance that, pursuant to paragraph 6 of the challenged Art. 7-quater, the derogations in question are allowed "only in cases where it is not possible to modify the original characteristics of the openings or create new ones" does not allow the exclusion of the alleged constitutional legitimacy flaw.

It is true that, as the regional defense recalls, in judgment no. 119 of 2024, point 17 of the Findings of Law, this Court deemed the requirements referred to in M.D. 5 July 1975 derogable for attics, but such possibility was recognized "in consideration of the nature of lex specialis of the discipline relating to habitability requirements [...] concerning height and air-lighting" of that specific category of premises. Therefore, the solution accepted therein cannot – as the respondent erroneously deduces – extend, in a generalized way, to all buildings that due to their architectural characteristics cannot be modified.

In conclusion, by reason of the constitutional importance of the good protected through the prescriptions of M.D. 5 July 1975, these cannot be derogated in a generalized way by regions, even if with a special statute, because this determines a wound to the fundamental right to health.

11.3.– The constitutional illegitimacy of Art. 12 of Sardinia Regional Law no. 18 of 2025, in the part where, by modifying Art. 7-quater, paragraphs 3, letters e) and d), and 6, of Sardinia Regional Law no. 23 of 1985, it allows derogating from the prescriptions on air-lighting requirements referred to in M.D. of 5 July 1975, must therefore be declared, for violation of Art. 32 of the Constitution.

12.– The President of the Council of Ministers (in the first part of the seventh ground of appeal) challenges Art. 12 of Sardinia Regional Law no. 18 of 2025, also in the part where, by modifying Art. 7-quater, paragraph 1, of Sardinia Regional Law no. 23 of 1985, it provided that in matters of property habitability and derogations from hygienic-sanitary requirements, paragraphs 5-bis, 5-ter and 5-quater of Art. 24 TUEd do not find application.

According to the appellant, the provision would be constitutionally illegitimate for violation of Art. 117, second paragraph, letter m), of the Constitution, in relation to Art. 24, paragraphs from 5-bis to 5-quater, TUEd, "in that the matter relating to building standards is configured as an" essential level of service that must be guaranteed throughout the national territory. The passage reported above exhausts, in essence, the motivation in support of the violation of the evoked constitutional parameter, so the grievance must be declared inadmissible.

Constitutional jurisprudence is constant in affirming that "''the need for adequate motivation as the basis of the challenge arises in rigorous terms in proceedings proposed in the principal instance, in which the appellant has the burden not only of identifying the challenged provisions and the constitutional parameters of which it alleges the violation, but also of supporting the reasons for the deduced conflict with clear, complete and sufficiently articulated arguments (ex multis, judgments no. 125 of 2023, no. 265, no. 259 and no. 135 of 2022, no. 170 of 2021 and no. 279 of 2020)' (judgment no. 169 of 2024)" (judgment no. 196 of 2025, point 6.7.1. of the Findings of Law; similarly, judgments no. 126, point 4.1. of the Findings of Law, and no. 106, point 2.1. of the Findings of Law, of 2025).

This burden has not been adequately discharged. The appeal, indeed, dwells at length on the sole reconstruction of the state discipline referred to in the cited paragraphs from 5-bis to 5-quater of Art. 24, but does not develop arguments in support of the alleged violation of Art. 117, second paragraph, letter m), of the Constitution, handing over to the examination of this Court a grievance supported by insufficient and clearly assertive motivation.

13.– With the third ground of appeal, Art. 4 of Sardinia Regional Law no. 18 of 2025 is challenged, in the part where it introduces paragraph 3-bis into Art. 3-bis of Sardinia Regional Law no. 23 of 1985 and allows that the interventions contemplated by it be performed in derogation from the minimum protection distances for the railway line.

The cited Art. 3-bis, paragraph 3-bis, provides that "In the case of energy requalification interventions on buildings existing at the date of 24 May 2024, provided that the intervention ensures a minimum reduction of 10 percent of the transmittance limits provided for by Legislative Decree no. 192 of 19 August 2005 (Implementation of Directive (EU) 2018/844, amending Directive 2010/31/EU on energy performance in buildings and Directive 2012/27/EU on energy efficiency, of Directive 2010/31/EU, on energy performance in buildings, and of Directive 2002/91/EC regarding energy yield in buildings), and subsequent amendments and integrations, certified with the methods provided for by the same legislative decree, the thickness of the external walls and of the superior and inferior closure elements that enclose the heated volume, is not calculated in the determination of volumes, heights, surfaces and coverage ratios, up to a maximum of 30 cm compared to the real measure. The provision referred to in the previous period applies in derogation from the provisions of regional regulations and municipal building codes, as well as minimum distances between buildings, minimum distances from boundaries, minimum protection distances for the road and railway line and similar. Derogations are to be exercised in compliance with minimum distances reported in the civil code."

In the appellant's opinion, the challenged provision, in allowing the minimum protection distances for the railway line to be disregarded, would conflict with the discipline provided by Arts. 49 and 60 of P.D. no. 753 of 1980 and would violate, consequently, for one side, Art. 3 of the Special Statute, as the aforesaid provisions are qualifiable as fundamental norms of economic-social reform, and, for the other, Art. 117, second paragraph, letter h), of the Constitution, still in relation to the cited regulatory legislation, in that it would have invaded the exclusive state legislative competence in the matter of "public order and security."

13.1.– The issue promoted with reference to Art. 3 of the Special Statute is founded.

Art. 49 of P.D. no. 753 of 1980 provides that "Along the tracks of railway lines it is forbidden to build, reconstruct or expand buildings or structures of any kind at a distance, to be measured in horizontal projection, less than thirty meters from the boundary of the occupation zone of the nearest rail." Art. 60 of the cited P.D. establishes, instead, that such distance can be derogated upon authorization by the Italian Railway Network Company "When public safety, the conservation of railways, the nature of the terrain and particular local circumstances allow it," upon request of the interested parties (paragraph 1). Provision is made, furthermore, that the "competent offices [...] before authorizing the requested reductions of the prescribed legal distances, give, by registered letter with advice of receipt, communication to the interested companies of the requests received, assigning them a peremptory term of thirty days for the presentation of any observations" (paragraph 2), after which "the aforementioned offices can authorize the requested reductions" (paragraph 3).

The challenged regional norm explicitly and directly derogates from the minimum distance of 30 meters provided for by state discipline, in Art. 49 of the cited P.D. and, consequently, also from the cited Art. 60, by force of which, as seen, the realization of building interventions that do not respect such distance must be authorized by the competent offices on a case-by-case basis.

It must be considered, in fact, that, among the conditions that the competent offices must evaluate to grant the derogation from the distance provided by state legislation, a preeminent role is covered by that concerning the maintenance of safety. A condition, this, which "requires, first of all, the necessity of conserving adequate spaces on the sides of the railway with the purpose of safeguarding the possibility of executing rescue interventions in line in case of railway incidents." Therefore, the possibility of derogating from such distance, even if provided for by state legislation, must always be subordinated to the positive evaluation that it does not compromise in practice "the possibility of easily executing rescue interventions (safety) or service public implementations in operation" (Council of State, Fourth Section, judgment no. 8324 of 17 October 2024).

The argument spent by the respondent does not result, moreover, founded, namely that the derogation introduced by regional regulation would not be in any way capable of conditioning the activity of the competent offices referred to in the cited Art. 60.

The challenged regional regulation conditions, in fact, inevitably the activity of such offices, which would find themselves forced to authorize the aforementioned interventions, determining an applicative non-homogeneity compared to other parts of the national territory.

In definitive, the challenged regional regulation conflicts with the state discipline evoked as an interposed parameter, which, based on the criteria outlined by this Court's jurisprudence, must be attributed to the fundamental norms of economic-social reform. It, in fact, by disciplining the sector of railway transport safety, expresses a reformist content, concerns sectors or goods of economic-social life of significant importance and responds "''overall to a unitary interest''" that demands "''an implementation [homogeneous] throughout the national territory' (judgment no. 1033 of 1988)" (judgment no. 198 of 2018, point 18.7. of the Findings of Law).

13.2.– It must, in conclusion, be declared the constitutional illegitimacy of Art. 4 of Sardinia Regional Law no. 18 of 2025, in the part where it introduces paragraph 3-bis into Art. 3-bis of Sardinia Regional Law no. 23 of 1985, limited to the words "and railway," for violation of Art. 3 of the Special Statute.

The further grievances remain absorbed.

14.– The appellant requested, with the fourth ground of appeal, to declare the constitutional illegitimacy of Art. 4 of Sardinia Regional Law no. 18 of 2025, also in the part where it introduces paragraph 3-ter into Art. 3-bis of Sardinia Regional Law no. 23 of 1985.

In the specific case, the State challenges the cited regional provision in that it provides that, even for the realization of new buildings, the thickness of external walls and superior and inferior closure elements that enclose the heated volume, as well as intermediate floors, for interventions aimed at increasing the energy efficiency of such buildings, are not to be calculated in the determination of volumes and maximum building height.

In the opinion of the State Attorney General, the referenced provision would conflict with state discipline, as resulting from the repeal of Art. 14, paragraph 6, of Legislative Decree no. 102 of 2014, occurred via Art. 13, paragraph 1, letter a), of Legislative Decree no. 73 of 2020.

Due to the effect of such repeal, the exclusions contemplated by the challenged regional norm would be allowed by state discipline only for interventions on existing buildings.

By allowing them also for new buildings, the Sardinian legislator would have, therefore, violated, in the first place, the principle of loyal cooperation referred to in Arts. 5 and 120 of the Constitution, in that the obligation of concerted and shared planning would be eluded, necessary for orderly urban development and for identifying transformations compatible with the state prescriptions of the code of cultural heritage and landscape.

In the second place, the challenged norm would also conflict with Art. 117, second paragraph, letter l), of the Constitution, in matters of civil law, in that, always in not distinguishing between new buildings and existing buildings, it would introduce "derogat[ions] of such significance that, if allowed, they would undermine the essence and function of the planning principle underlying even the intervention of the 2020 state legislator."

14.1.– The issues must be declared inadmissible, in that the motivation in support of the challenge is lacking and merely assertive.

The appellant, in fact, has not adequately discharged the burden of motivation requested in the principal instance. In the first place, the appeal, in alleging the failure to respect the planning principle in reference to the principle of loyal cooperation is not supported by an adequate argumentative framework, it being difficult to understand why, and to what extent, the recalled constitutional principle would be violated. In the second place, also the alleged wound to the planning principle, alleged in reference to Art. 117, second paragraph letter l), of the Constitution, is supported by a merely assertive motivation, to the point that neither are explained, and from the elements offered do not even result understandable, the reasons for which the planning principle should be led back within the scope of exclusive state legislative competence in matters of civil law.

14.2.– The issues of constitutional legitimacy of Art. 4 of the challenged regional law, in the part where it introduces paragraph 3-ter into Art. 3-bis of Sardinia Regional Law no. 23 of 1985, must therefore be declared inadmissible.

15.– In the second part of the seventh ground of appeal, the State challenges Art. 12 of Sardinia Regional Law no. 18 of 2025, where, by modifying Art. 7-quater, paragraph 1, of Sardinia Regional Law no. 23 of 1985, it provided that in matters of property habitability and derogations from hygienic-sanitary requirements, paragraphs 5-bis, 5-ter and 5-quater of Art. 24 TUEd do not find application.

According to the appellant, the provision would be constitutionally illegitimate for violation of Art. 117, second paragraph, letter m), of the Constitution, in relation to Art. 24, paragraphs from 5-bis to 5-quater, TUEd, "in that the matter relating to building standards is configured as an" essential level of service that must be guaranteed throughout the national territory. The passage reported above exhausts, in essence, the motivation in support of the violation of the evoked constitutional parameter, so the grievance must be declared inadmissible.

Constitutional jurisprudence is constant in affirming that "''the need for adequate motivation as the basis of the challenge arises in rigorous terms in proceedings proposed in the principal instance, in which the appellant has the burden not only of identifying the challenged provisions and the constitutional parameters of which it alleges the violation, but also of supporting the reasons for the deduced conflict with clear, complete and sufficiently articulated arguments (ex multis, judgments no. 125 of 2023, no. 265, no. 259 and no. 135 of 2022, no. 170 of 2021 and no. 279 of 2020)' (judgment no. 169 of 2024)" (judgment no. 196 of 2025, point 6.7.1. of the Findings of Law; similarly, judgments no. 126, point 4.1. of the Findings of Law, and no. 106, point 2.1. of the Findings of Law, of 2025).

This burden has not been adequately discharged. The appeal, indeed, dwells at length on the sole reconstruction of the state discipline referred to in the cited paragraphs from 5-bis to 5-quater of Art. 24, but does not develop arguments in support of the alleged violation of Art. 117, second paragraph, letter m), of the Constitution, handing over to the examination of this Court a grievance supported by insufficient and clearly assertive motivation.

16.– With the second ground of appeal, Art. 2 of Sardinia Regional Law no. 18 of 2025 is challenged, in the part where it introduces Art. 2-ter, paragraph 2, into Sardinia Regional Law no. 23 of 1985.

Such provision establishes that "In properties subject to building amnesty realized in conflict with urban planning norms are allowed, without volumetric or covered surface area increase, solely works of ordinary maintenance, extraordinary maintenance, restoration and conservative rehabilitation, building renovation not involving demolition and reconstruction with different outline. Specific normative provisions having purposes of urban regeneration and redevelopment as well as renewal of building stock are saved. For the properties referred to in the first sentence it is, in any case, always allowed the demolition and subsequent reconstruction in compliance with building and urban planning norms in force."

In the first place, the appellant alleges the violation of Arts. 3 of the Special Statute and 117, second paragraph, letter s), of the Constitution, in relation to Art. 9-bis, paragraph 1-bis, TUEd, since the regional legislator would have introduced an "obstructive 'constraint'" for the execution of interventions on properties or real estate units which, in that they are subject to building amnesty, should be considered legitimately existing and regularly assented, according to what is provided by the evoked Art. 9-bis, paragraph 1-bis.

The regional norm would also violate Art. 42, second paragraph, of the Constitution, since it would cause prejudice to the private property owner of the property who, even though not expropriated of the relative title, sees limited the power to carry out certain building interventions on a property or real estate unit.

16.1.– The issues are not founded.

The appellant makes his grievances derive from the assumption that the amnesty would be a title that determines "the legitimate status" of the property pursuant to Art. 9-bis, paragraph 1-bis, TUEd, deducing from this that the owner of the amnestied property could not see limited his power to carry out volumetric increase interventions.

Such assumption is however devoid of foundation.

It is necessary first of all to recall that, through amnesty regulations (Art. 31 of Law no. 47 of 28 February 1985, containing "Rules regarding control of building activity, sanctions, recovery and regularization of abusive works"; Art. 39 of Law no. 724 of 23 December 1994, containing "Measures for rationalization of public finance" and Art. 32 of Decree-Law no. 269 of 30 September 2003, containing "Urgent provisions to favor development and for the correction of the performance of public accounts," converted, with amendments, into Law no. 326 of 24 November 2003), "the national legislator, in an extraordinary way and with ad hoc rules, has allowed the regularization of abuse situations, perpetrated until a certain date, of a substantial nature, in that in conflict with urban planning-building discipline (among others, judgments no. 42 of 2023, no. 68 of 2018, no. 232 and no. 50 of 2017)" (judgment no. 142 of 2024, point 6.6.2.1. of the Findings of Law).

The amnesty, therefore, is a measure absolutely "extra ordinem and destined to operate a tantum in view of a definitive overcoming of abuse situations" (judgment no. 181 of 2021, point 10.1. of the Findings of Law) and "does not elide the situation of illegality, but operates only on two levels and in particular 'on the criminal level, upon the occurrence of the legal prerequisites, determines the extinction of building crimes [and] on the administrative one entails the achievement of the concession in amnesty (and the extinction of the administrative offense)' (judgments no. 44 of 2023 and no. 70 of 2008)" (still judgment no. 142 of 2024, point 6.6.2.1. of the Findings of Law).

From the limited scope of extraordinary amnesties follows that "the property that is its object cannot benefit from regulations that recognize building advantages that exceed interventions of maintenance, ordinary or extraordinary, and renovation aimed at the protection of the integrity of the construction and the conservation of its functionality" (still judgment no. 142 of 2024, point 6.6.2.1. of the Findings of Law). It was moreover clarified that the prohibition of recognizing "building benefits for abusive properties [...] rises to the principle of the legal system of the Republic and, as such, constitutes a limit to the primary legislative power" of regions with special statutes (still judgment no. 142 of 2024, point 6.6.2. of the Findings of Law, and, in a similar sense, judgment no. 24 of 2022, point 5.3.2. of the Findings of Law).

Therefore, the limits set by the challenged norm are coherent with the extraordinary character and with the effects of building amnesty and do not conflict with the evoked parameters.

16.2.– Such conclusion does not change, and indeed is confirmed, also taking into consideration what is provided by Art. 1, paragraph 23, of Law no. 199 of 30 December 2025 (State budget forecast for the financial year 2026 and multi-year budget for the three-year period 2026-2028), which amended paragraph 10 of Art. 5 of Decree-Law no. 70 of 13 May 2011 (European Semester - First urgent provisions for the economy), converted, with amendments, into Law no. 106 of 12 July 2011.

The cited Art. 5, in paragraph 9, establishes that "In order to incentivize the rationalization of existing building stock as well as to promote and facilitate the redevelopment of degraded urban areas with the presence of heterogeneous functions and disorganized or unfinished building fabrics as well as non-residential buildings abandoned or in the process of decommissioning or to be relocated, taking into account also the need to favor the development of energy efficiency and renewable sources, the Regions approve within sixty days from the date of entry into force of the conversion law of this decree specific laws to incentivize such actions also with demolition and reconstruction interventions that provide for:

a) the recognition of an additional volume compared to the pre-existing one as a premium measure;

b) the relocation of relative volumes in a different area or areas;

c) the admissibility of intended use modifications, provided they are destinations that are compatible or complementary to each other;

d) the modifications of the outline necessary for architectural harmonization with existing building organisms."

Following the amendment in question, paragraph 10, which concerns us here, establishes that "The interventions referred to in paragraph 9 cannot refer to abusive buildings or located in historical centers or in areas of absolute inedifiability, with the exclusion of buildings for which the building enabling title in amnesty has been issued or achieved, also pursuant to Law no. 47 of 28 February 1985, Law no. 724 of 23 December 1994, and Decree-Law no. 269 of 30 September 2003, converted, with amendments, by Law no. 326 of 24 November 2003."

In substance, with the recalled legislation, the state legislator intended to allow, for the purposes expressly indicated, volumetric increases also for properties subject to amnesty and, incidentally, the circumstance must be highlighted that such legislation is already capable of exerting its own effects in the Sardinian regional legal system, in that Art. 2-ter, paragraph 2, of Sardinia Regional Law no. 23 of 1985 expressly saves specific regulatory provisions having purposes of urban regeneration and redevelopment, as well as renewal of building stock.

The recalled legislative amendment does not disprove, however, the conclusions reached here, for the absorbing reason that, if even the state legal system today admits that amnestied properties benefit from volumetric rewards from which they are generally excluded, such possibility is recognized only with respect to predetermined (however broad) purposes.

In other words, the amended Art. 5, paragraph 10, acts as a special norm which, as such, confirms the general principle of the prohibition of volumetric benefits, deriving from the extra ordinem nature of building amnesty.

16.3.– Having clarified this, the challenged regional regulation, by preventing, on one hand, volumetric increases and allowing, on the other, the realization of interventions aimed at the protection of the integrity of the construction and the conservation of its functionality, is entirely compliant with the regulatory and jurisprudential framework in building matters.

Moreover, the regional legislator, by allowing interventions aimed at protecting the integrity of the construction, has not even harmed the constitutional statute of the right to property, referred to in the evoked Art. 42, second paragraph, of the Constitution, given that, as this Court had the opportunity to clarify in judgment no. 238 of 2000, point 3 of the Findings of Law, only those provisions that hinder interventions "having as their sole purpose the protection of the integrity of the construction and the conservation of its functionality, without altering the external appearance (outline and volumetry) of the building" must be considered conflicting with the cited constitutional parameter.

16.4.– The issues of constitutional legitimacy of Art. 2 of Sardinia Regional Law no. 18 of 2025, in the part where it introduces Art. 2-ter, paragraph 2, into Sardinia Regional Law no. 23 of 1985, promoted with reference to Arts. 3 of the Special Statute, 117, second paragraph, letter s), and 42, second paragraph, of the Constitution must be, therefore, declared unfounded.

17.– The President of the Council of Ministers, with the eighth ground of appeal, also doubts the constitutional legitimacy of Art. 14 of Sardinia Regional Law no. 18 of 2025, in the part where it "makes amendments to Article 11 of regional law no. 23 of 1985, regarding urban-relevant functional categories and intended use," alleging the conflict with Arts. 3 of the Special Statute and 117, second paragraph, letter s), of the Constitution, in relation to Art. 23-ter TUEd.

In the appellant's opinion, the Sardinian legislator would not have transposed the innovations introduced by the cited state provision regarding the obligations related to the satisfaction of urban planning fees connected to the change of intended use of individual real estate units, both within the same functional category (so-called urbanistically irrelevant or horizontal intended use changes), and between different functional categories (so-called urbanistically relevant or vertical changes).

17.1.– The issues must be declared inadmissible, in that the appellant has not adequately discharged the burden of motivation requested in the principal instance.

The appeal dwells at length on the reconstruction of the new state discipline, but does not pause neither to identify the specific provisions of the challenged Art. 14 that would be in conflict with the cited Art. 23-ter, nor, on the other hand, to illustrate more generally the reasons for which the challenged regional discipline would not be compliant with the state legislation evoked as an interposed parameter.

The appellant then, in the meager arguments exposed in acts, has not even punctually confronted himself with the regulatory scope of the cited Art. 23-ter, which, in its paragraph 3, provides that the state discipline finds immediate implementation, waiting for regions to comply with the obligation to adapt. The appeal, therefore, has not even adequately considered the regulatory context in which the challenged regional provision fits, incurring a further profile of inadmissibility.

It must therefore be declared the inadmissibility of the issues promoted with reference to Arts. 3 of the Special Statute and 117, second paragraph, letter s), of the Constitution.

18.– Lastly, the State challenges, with the ninth ground of appeal, Art. 18, paragraph 1, letter a), of Sardinia Regional Law no. 18 of 2025, which, modifying Art. 15-quater, paragraph 1, of Sardinia Regional Law no. 23 of 1985, provides that in changes of intended use that are not urbanistically relevant, without prejudice to compliance with parking spaces provided for by specific sector regulations, the municipal urban planning instrument determines the parking spaces eventually deemed necessary.

The State alleges the violation of Arts. 3 of the Special Statute and 117, second paragraph, letter s), of the Constitution, in relation to Art. 23-ter of the Consolidated Act on Building, in that, contrary to what is prescribed by the cited state provision, the Sardinian regional legislator would have continued to provide for the obligation of mandatory minimum parking allocation for changes of intended use so-called horizontal.

18.1.– The issue of constitutional legitimacy promoted for violation of Art. 3 of the Special Statute is founded.

18.1.1.– It is appropriate, first of all, to delineate the essential traits of the discipline on the change of intended use referred to in the cited Art. 23-ter, also in light of the amendments made to it by Decree-Law no. 69 of 2024, as converted.

For what concerns us here, the change of intended use can qualify as "urbanistically relevant" (also called "vertical") or "urbanistically irrelevant" (or "horizontal").

It is considered "urbanistically relevant" when it marks the passage from one to another of the five functional categories listed also by the cited Art. 23-ter, paragraph 1 – a) residential; a-bis) tourist-hotel; b) productive and directional; c) commercial; d) rural –, in that, regardless of any increase in volumes and/or surfaces, the different use entails a change in the quality and quantity of connected services, integrating a modification that affects the urban load originally provided for, with the consequent burden of services. The change of intended use, instead, is considered urbanistically irrelevant when it occurs within the same functional category and does not determine any aggravation of the existing urban load, since it is presumed that within each of the functional categories the urban load is analogous.

As already recalled, on such discipline intervened Decree-Law no. 69 of 2024, as converted, which, in its Art. 1, paragraph 1, letter c), amended Art. 23-ter TUEd, in the perspective of introducing simplification measures.

For what directly concerns the issues at today's examination, pursuant to the new paragraph 1-bis of this article, "The change of intended use of the individual real estate unit within the same functional category is always allowed, in compliance with sector regulations, without prejudice to the possibility for municipal urban planning instruments to fix specific conditions."

As regards, instead, the urbanistically relevant change, the new paragraph 1-ter of the same article provides that it is always allowed that:

- between the functional categories referred to in paragraph 1, letters a) (residential), a-bis) (tourist hotel), b) (productive and directional) and c) (commercial);

- of an individual real estate unit, located in properties included in zones A), B) and C) referred to in Art. 2 of M.D. no. 1444 of 1968, "in equivalent zones as defined by regional laws in the matter, in compliance with the conditions referred to in paragraph 1-quater and sector regulations and without prejudice to the possibility for municipal urban planning instruments to fix specific conditions."

The urban planning regime of the change of intended use of the individual real estate unit referred to in the mentioned paragraph 1-ter is disciplined by paragraph 1-quater. Such paragraph, reiterating that said change is "always allowed," both with works and without works, without prejudice to the possibility for municipal urban planning instruments to fix specific conditions, including the finalization of the change to the prevalent destination in other real estate units present in the property, provides that:

a) the change in question is not subject to the obligation of finding further areas for general interest services, provided for by M.D. no. 1444 of 1968 and by regional law provisions, nor to the constraint of mandatory minimum parking allocation provided for by Law no. 1150 of 17 August 1942;

b) the payment of the contribution requested for secondary urbanization charges remains firm within the limits of what is established by regional legislation, where provided for.

As the President of the Council of Ministers recalls, the purpose of the amendments introduced with Decree-Law no. 69 of 2024, as converted, is that of facilitating changes of intended use; a purpose that finds justification in the circumstance that, in zones A), B) and C) referred to in Art. 2 of M.D. no. 1444 of 1968, such change occurs tendentially in an already urbanized context, where the increase of urban load is therefore assumed compensated or resized.

From this derives the provision that it is not necessary to correspond primary urbanization charges, in that the relative request would translate into a substantial duplication of costs in the face of the uniqueness of the services already provided in the area concerned. Instead, the payment of the contribution requested for secondary urbanization charges continues to be due, where provided for and within the limits of what is established by regional legislation, which cannot be considered as an automatic duplication of costs, in that they are functional to the relationship life of the inhabitants of the area concerned (on urbanization charges see, lastly, also judgment no. 61 of 2026, point 9 of the Findings of Law).

18.1.2.– Having premised this, the challenged regional norm, by keeping firm the obligation of parking allocation for changes of intended use so-called horizontal, conflicts with the discipline referred to in the cited Art. 23-ter.

In order to support the legitimacy of the Sardinian regional legislator's intervention, the respondent deduces that the exemption from the obligation of minimum parking allocation of the evoked state discipline would find application solely for changes of intended use so-called vertical.

The thesis cannot find acceptance.

Even if – as the regional defense notes – the letter of the cited Art. 23-ter, paragraph 1-quater, makes reference only to the change of intended use so-called vertical, the interpretation of the discipline in its complex induces to conclude in the sense that the exemption in question necessarily extends also to changes of intended use so-called horizontal.

As has already been recalled, in fact, in the structure resulting from the amendments introduced by Decree-Law no. 69 of 2024, as converted, the change of intended use within the same functional category is supported by the principle of functional indifference between homogeneous intended uses, in that it is presumed that, in these hypotheses, such change does not entail significant variations of the corresponding urban loads, i.e., does not affect the need for territorial endowments, such as, for example, precisely spaces intended for parking.

In light of the systematic interpretation of the discipline introduced by the amended Art. 23-ter, the exemption from the constraint of parking allocation, expressly provided for changes so-called vertical, must, therefore, necessarily be extended also to horizontal ones.

Moreover, if said exemption were not to be considered operating also for these latter ones, one would arrive at the paradoxical conclusion that the constraint in question would not apply to changes of intended use so-called vertical, which entail a greater aggravation on urban load, but would apply to horizontal ones, which entail a lesser one.

In definitive, the challenged regional discipline is different from the discipline deducible from the systematic reading of the cited Art. 23-ter, paragraph 1-ter, which, as a fundamental norm of economic-social reform, operates as a general limit to the exercise of the primary legislative power of the Autonomous Region of Sardinia in matters of building and urban planning. It, in fact, is characterized by the innovativeness of the regulatory content, taken also into account the purpose of simplification of the discipline of changes of intended use of properties and real estate units, with the regulation of charges and connected obligations, and therefore certainly concerns a sector of significant importance that demands uniform implementation throughout the national territory.

18.2.– The constitutional illegitimacy of Art. 18, paragraph 1, letter a), of the challenged regional law must therefore also be declared, for violation of Art. 3 of the Special Statute.

The further grievances remain absorbed.

for these reasons

THE CONSTITUTIONAL COURT

reserving to a separate pronouncement the decision on the further issues of constitutional legitimacy promoted with the appeal indicated in the heading;

1) declares the constitutional illegitimacy of Art. 2 of the Sardinia Regional Law 17 June 2025, no. 18 (Reorganization and coordination of regional building and urban planning regulations with the urgent provisions regarding urban planning and building simplification referred to in Decree-Law no. 69 of 29 May 2024, converted, with amendments, into Law no. 105 of 24 July 2024), in the part where it introduces Art. 2-bis, paragraph 3, into the Sardinia Regional Law 11 October 1985, no. 23 (Regional rules for the control of urban building activity);

2) declares the constitutional illegitimacy of Art. 4 of the Sardinia Regional Law no. 18 of 2025, in the part where it introduces Art. 3-bis, paragraph 3-bis, into the Sardinia Regional Law no. 23 of 1985, limited to the words "and railway";

3) declares the constitutional illegitimacy of Art. 6 of the Sardinia Regional Law no. 18 of 2025, in the part where it introduces Art. 4, paragraph 2, into the Sardinia Regional Law no. 23 of 1985;

4) declares the constitutional illegitimacy of Art. 7, paragraph 1, letter d), of the Sardinia Regional Law no. 18 of 2025;

5) declares the constitutional illegitimacy of Art. 12 of the Sardinia Regional Law no. 18 of 2025, in the part where, introducing Art. 7-quater, paragraphs 3, letters d) and e), and 6, into the Sardinia Regional Law no. 23 of 1985, it allows derogating from air-lighting parameters referred to in the Decree of the Minister of Health of 5 July 1975 (Amendments to ministerial instructions of 20 June 1896 regarding minimum height and main hygienic-sanitary requirements of residential premises);

6) declares the constitutional illegitimacy of Art. 18, paragraph 1, letter a), of the Sardinia Regional Law no. 18 of 2025;

7) declares the constitutional illegitimacy of Art. 19 of the Sardinia Regional Law no. 18 of 2025, in the part where it introduces Art. 16, paragraph 3, into the Sardinia Regional Law no. 23 of 1985;

8) declares inadmissible the issues of constitutional legitimacy of Art. 2 of the Sardinia Regional Law no. 18 of 2025, in the part where it introduces Art. 2-bis, paragraph 5, into the Sardinia Regional Law no. 23 of 1985, promoted, with reference to Arts. 3 and 97 of the Constitution, by the President of the Council of Ministers with the appeal indicated in the heading;

9) declares inadmissible the issues of constitutional legitimacy of Art. 4 of the Sardinia Regional Law no. 18 of 2025, in the part where it introduces paragraph 3-ter into Art. 3-bis, of the Sardinia Regional Law no. 23 of 1985, promoted, with reference to Arts. 5, 120 and 117, second paragraph, letter l), of the Constitution, by the President of the Council of Ministers with the appeal indicated in the heading;

10) declares inadmissible the issue of constitutional legitimacy of Art. 12 of the Sardinia Regional Law no. 18 of 2025, in the part where it introduces Art. 7-quater, paragraph 1, into the Sardinia Regional Law no. 23 of 1985, promoted, with reference to Art. 117, second paragraph, letter m), of the Constitution, by the President of the Council of Ministers with the appeal indicated in the heading;

11) declares inadmissible the issues of constitutional legitimacy of Art. 14 of the Sardinia Regional Law no. 18 of 2025, promoted, with reference to Arts. 117, second paragraph, letter s), of the Constitution and 3 of the Sardinia Regional Statute, by the President of the Council of Ministers with the appeal indicated in the heading;

12) declares inadmissible the issues of constitutional legitimacy of Art. 15 of the Sardinia Regional Law no. 18 of 2025, promoted, with reference to Arts. 117, second paragraph, letter s), of the Constitution and 3 of the Sardinia Regional Statute, by the President of the Council of Ministers with the appeal indicated in the heading;

13) declares unfounded, in the terms of the motivation, the issues of constitutional legitimacy of Art. 2 of the Sardinia Regional Law no. 18 of 2025, in the part where it introduces Art. 2-bis, paragraph 5, into the Sardinia Regional Law no. 23 of 1985, promoted, with reference to Arts. 117, second paragraph, letter s), of the Constitution and 3 of Constitutional Law no. 3 of 26 February 1948 (Special Statute for Sardinia), by the President of the Council of Ministers with the appeal indicated in the heading;

14) declares unfounded the issues of constitutional legitimacy of Art. 2 of the Sardinia Regional Law no. 18 of 2025, in the part where it introduces Art. 2-ter, paragraph 2, into the Sardinia Regional Law no. 23 of 1985, promoted, with reference to Arts. 117, second paragraph, letter s), and 42, second paragraph, of the Constitution and Art. 3 of the Sardinia Regional Statute, by the President of the Council of Ministers with the appeal indicated in the heading.

Thus decided in Rome, at the seat of the Constitutional Court, Palazzo della Consulta, on 25 March 2026.

Signed:

Giovanni AMOROSO, President

Maria Alessandra SANDULLI, Reporting Justice

Igor DI BERNARDINI, Clerk

Filed in the Registry on 21 May 2026