SU and Wild Ireland Defence CLG v An Coimisiún Pleanála and Others (C-27/25)

Contents

Judgment of the Court (Fourth Chamber)16 July 2026^note(References for a preliminary ruling — Environment — Directive 92/43/EEC — Directive 2009/147/EC — Conservation of natural habitats and of wild fauna and flora — Special protection areas — Appropriate assessment of the implications of a plan or project likely to have an effect on a protected site in view of that site’s conservation objectives — Screening — Conservation objectives specific to a special protection area not set)In Joined Cases C‑27/25 and C‑356/25,TWO REQUESTS for a preliminary ruling under Article 267 TFEU from the Court of Appeal (Ireland) (C‑27/25) and the High Court (Ireland) (C‑356/25), made by decisions of 13 December 2024 and of 11 April 2025, received at the Court on 17 January 2025 and 27 May 2025 respectively, in the proceedingsSU,Wild Ireland Defence CLGvAn Coimisiún Pleanála, previously known as An Bord Pleanála,Minister for Housing, Local Government and Heritage,Ireland,The Attorney General,notice party:Knocknamona Windfarm Limited (C‑27/25),Paddy MasseyvAn Coimisiún Pleanála, previously known as An Bord Pleanála,Ireland,The Attorney General,Minister for Housing, Local Government and Heritage,notice party:Curns Energy Limited (C‑356/25),THE COURT (Fourth Chamber),composed of I. Jarukaitis, President of the Chamber, M. Condinanzi, N. Jääskinen, R. Frendo and A. Kornezov (Rapporteur), Judges,Advocate General: J. Kokott,Registrar: C. Strömholm, Administrator,having regard to the written procedure and further to the hearing on 25 March 2026,after considering the observations submitted on behalf of:– SU and Wild Ireland Defence CLG, by J. Devlin, Senior Counsel, M. Heavey, Barrister-at-Law, and B. Harrington, Solicitor,– Paddy Massey, by J. Devlin, Senior Counsel, M. Heavey, Barrister-at-Law, and B. Harrington, Solicitor,– An Coimisiún Pleanála, by F. Valentine, Senior Counsel, S. Hughes, Barrister-at-Law, S. O’Connor, Barrister-at-Law, R. McDermott, A. McKenna, R. Minch, G. Murphy, A. O’Connor and M. O’Leary, Solicitors,– the Minister for Housing, Local Government and Heritage, Ireland, the Attorney General and Ireland, by M. Browne, A. Burke, H. Ignatova and A. Joyce, acting as Agents, and by M. Gray, Senior Counsel, E. Synnott, Barrister-at-Law, and S. Keniry, Barrister-at-Law,– Knocknamona Windfarm Limited, by N. Dunleavy, Senior Counsel, J. Fitzsimons, Senior Counsel, T. O’Sullivan, Barrister-at-Law, M. Delargy and J. Hurley, Solicitors,– Curns Energy, by S. Dodd, Senior Counsel, C. Hughes, Barrister-at-Law, H. Gallagher, D. Nagle and G. Tiernan, Solicitors,– the European Commission, by B. Cullen and N. Ruiz García, acting as Agents,after hearing the Opinion of the Advocate General at the sitting on 16 April 2026,gives the following

Judgment

1These two requests for a preliminary ruling concern the interpretation of Article 6(3) of Council Directive 92/43/EEC of 21 May 1992 on the conservation of natural habitats and of wild fauna and flora (OJ 1992 L 206, p. 7; ‘the Habitats Directive’).

2The two requests have been made in two sets of proceedings between, in Case C‑27/25, SU, a natural person, and Wild Ireland Defence CLG, an environmental organisation, on the one hand, and An Coimisiún Pleanála, previously known as An Bord Pleanála (Planning Commission, Ireland; ‘the Planning Commission’), the Minister for Housing, Local Government and Heritage (Ireland), Ireland and the Attorney General (Ireland), on the other hand, and, in Case C‑356/25, Mr Paddy Massey, also a natural person, on the one hand, and the Planning Commission, Ireland, the Attorney General and the Minister for Housing, Local Government and Heritage, on the other hand, concerning the lawfulness of two decisions, adopted by the Planning Commission, granting planning permission for amendments to, or the development of, wind farms.

Legal context

European Union law

The Birds Directive

3Article 3 of Directive 2009/147/EC of the European Parliament and of the Council of 30 November 2009 on the conservation of wild birds (OJ 2010 L 20, p. 7; ‘the Birds Directive’) provides, in paragraph 1 thereof, as follows:‘In the light of the requirements referred to in Article 2, Member States shall take the requisite measures to preserve, maintain or re-establish a sufficient diversity and area of habitats for all the species of birds referred to in Article 1.’

4Article 4 of the Birds Directive provides:1. The species mentioned in Annex I shall be the subject of special conservation measures concerning their habitat in order to ensure their survival and reproduction in their area of distribution.…Member States shall classify in particular the most suitable territories in number and size as special protection areas [(“SPAs”)] for the conservation of these species in the geographical sea and land area where this Directive applies.2. Member States shall take similar measures for regularly occurring migratory species not listed in Annex I, bearing in mind their need for protection in the geographical sea and land area where this Directive applies, as regards their breeding, moulting and wintering areas and staging posts along their migration routes. To this end, Member States shall pay particular attention to the protection of wetlands and particularly to wetlands of international importance.…4. In respect of the protection areas referred to in paragraphs 1 and 2, Member States shall take appropriate steps to avoid pollution or deterioration of habitats or any disturbances affecting the birds, in so far as these would be significant having regard to the objectives of this Article. Outside these protection areas, Member States shall also strive to avoid pollution or deterioration of habitats.’

The Habitats Directive

5The eighth and tenth recitals of the Habitats Directive state as follows:‘Whereas it is appropriate, in each area designated, to implement the necessary measures having regard to the conservation objectives pursued;…Whereas an appropriate assessment must be made of any plan or programme likely to have a significant effect on the conservation objectives of a site which has been designated or is designated in future’.

6The first subparagraph of Article 3(1) of the Habitats Directive provides:‘A coherent European ecological network of special areas of conservation shall be set up under the title Natura 2000. This network, composed of sites hosting the natural habitat types listed in Annex I and habitats of the species listed in Annex II, shall enable the natural habitat types and the species’ habitats concerned to be maintained or, where appropriate, restored at a favourable conservation status in their natural range.’

7Article 4 of the Habitats Directive provides:1. On the basis of the criteria set out in Annex III (Stage 1) and relevant scientific information, each Member State shall propose a list of sites indicating which natural habitat types in Annex I and which species in Annex II that are native to its territory the sites host. …The list shall be transmitted to the [European] Commission, within three years of the notification of this Directive, together with information on each site. …2. On the basis of the criteria set out in Annex III (Stage 2) …, the Commission shall establish, in agreement with each Member State, a draft list of sites of Community importance drawn from the Member States’ lists identifying those which lost one or more priority natural habitat types or priority species.…The list of sites selected as sites of Community importance … shall be adopted by the Commission …3. The list referred to in paragraph 2 shall be established within six years of the notification of this Directive.4. Once a site of Community importance has been adopted in accordance with the procedure laid down in paragraph 2, the Member State concerned shall designate that site as a special area of conservation [(“an SAC”)] as soon as possible and within six years at most, establishing priorities in the light of the importance of the sites for the maintenance or restoration, at a favourable conservation status, of a natural habitat type in Annex I or a species in Annex II and for the coherence of Natura 2000, and in the light of the threats of degradation or destruction to which those sites are exposed.5. As soon as a site is placed on the list referred to in the third subparagraph of paragraph 2 it shall be subject to Article 6(2), (3) and (4).’

8Article 6 of the Habitats Directive provides:1. For [SACs], Member States shall establish the necessary conservation measures involving, if need be, appropriate management plans specifically designed for the sites or integrated into other development plans, and appropriate statutory, administrative or contractual measures which correspond to the ecological requirements of the natural habitat types in Annex I and the species in Annex II present on the sites.2. Member States shall take appropriate steps to avoid, in the [SACs], the deterioration of natural habitats and the habitats of species as well as disturbance of the species for which the areas have been designated, in so far as such disturbance could be significant in relation to the objectives of this Directive.3. Any plan or project not directly connected with or necessary to the management of the site but likely to have a significant effect thereon, either individually or in combination with other plans or projects, shall be subject to appropriate assessment of its implications for the site in view of the site’s conservation objectives. In the light of the conclusions of the assessment of the implications for the site and subject to the provisions of paragraph 4, the competent national authorities shall agree to the plan or project only after having ascertained that it will not adversely affect the integrity of the site concerned and, if appropriate, after having obtained the opinion of the general public.4. If, in spite of a negative assessment of the implications for the site and in the absence of alternative solutions, a plan or project must nevertheless be carried out for imperative reasons of overriding public interest, including those of a social or economic nature, the Member State shall take all compensatory measures necessary to ensure that the overall coherence of Natura 2000 is protected. It shall inform the Commission of the compensatory measures adopted.…’

9Under Article 7 of the Habitats Directive:‘Obligations arising under Article 6(2), (3) and (4) of this Directive shall replace any obligations arising under the first sentence of Article 4(4) of [Council Directive 79/409/EEC of 2 April 1979 on the conservation of wild birds (OJ 1979 L 103, p. 1)] in respect of areas classified pursuant to Article 4(1) or similarly recognised under Article 4(2) thereof, as from the date of implementation of this Directive or the date of classification or recognition by a Member State under Directive 79/409/EEC, where the latter date is later.’

Irish law

10Section 177V(1) of the Planning and Development Act 2000, in the version applicable to the dispute in the main proceedings, provides that an appropriate assessment is to include a determination by the competent authority under Article 6(3) of the Habitats Directive as to whether or not a proposed development would adversely affect the integrity of a European site and must be carried out before consent is given for the proposed development. Section 177V(2) lists the matters which the competent authority is to take into account in carrying out an appropriate assessment, which include any information or advice obtained by or provided to the competent authority and any other relevant information. Section 177V(5) states that the competent authority is to give notice of its determination on that appropriate assessment to the applicant for consent to the proposed development, giving reasons for the determination.

The disputes in the main proceedings and the questions referred for a preliminary ruling

Case C‑27/25

11On 28 September 2022, the Planning Commission adopted a decision granting Knocknamona Windfarm Limited planning permission for a development that involved amending a wind farm, for which permission had been granted in 2016 in County Waterford (Ireland). That decision allowed the developer to increase the height both of the turbines, from 126 to 155 metres (m), and of the previously approved meteorological mast, which involved moving from a tubular tower mast of 80 m to a lattice tower mast of up to 99 m.

12Before adopting that decision, the Planning Commission carried out an appropriate assessment of the implications of that development for five European sites identified as likely to be affected by it, including the Blackwater Callows SPA, designated as a European site under the Birds Directive, located in the counties of Cork (Ireland) and Waterford and situated 13 kilometres (km) from the wind farm concerned.

13It is common ground that, on the date of adoption of that decision, Ireland had not yet set conservation objectives specific to that SPA.

14Relying in particular on its inspector’s report, the Planning Commission concluded that the qualifying interests of the site concerned included a number of species, including the whooper swan (Cygnus cygnus). As regards the other species, the Planning Commission concluded that any adverse effect on the integrity of that site could be excluded on the basis that the area covered by that project was unsuitable for any of those other species. In respect of the whooper swan, the Planning Commission did not find evidence of its presence in or close to that area and therefore concluded that the new dimensions of the mast, turbines and rotors would not have an adverse effect on the integrity of that site vis-à-vis that species. Therefore, the Planning Commission concluded that that development would not adversely affect the integrity of that area.

15SU and Wild Ireland Defence challenged the lawfulness of the Planning Commission’s decision before the High Court (Ireland). They maintain that, in the absence of conservation objectives set by Ireland specifically for the Blackwater Callows SPA, the Planning Commission could not carry out a valid appropriate assessment of the environmental implications of that development for that SPA.

16By its decision of 28 February 2024, the High Court dismissed the proceedings brought by SU and Wild Ireland Defence. According to that court, in essence, although the setting of conservation objectives specific to the SPA concerned is, in principle, necessary in order for a valid appropriate assessment of the implications of a plan or project for the protected site to be carried out, in the present case, the assessment, which had been carried out on the basis of the general conservation objectives, was still valid, since it was apparent from the scientific data that the whooper swan was not affected by the development at issue in the main proceedings, irrespective of what conservation objectives had specifically been set for the SPA concerned.

17The applicants in the main proceedings brought an appeal against the decision of the High Court before the Court of Appeal (Ireland), which is the referring court in Case C‑27/25. They submit that the wording of Article 6(3) of the Habitats Directive requires an appropriate assessment to be carried out of the implications of the proposed amendments for the site concerned ‘in view of the site’s conservation objectives’, with the result that it is possible to carry out a valid appropriate assessment only where specific conservation objectives have been adopted beforehand in respect of the SPA in question. The existence of general conservation objectives is therefore insufficient.

18In the context of those proceedings, the Planning Commission, the Minister for Housing, Local Government and Heritage, and the Advocate General, on the other hand, argue that, although it is true that the conservation objectives specific to the SPA in question must constitute a mandatory point of reference where they exist, there is no absolute preclusion on considering and carrying out an appropriate assessment of the implications of a plan or project for the site concerned in the absence of such objectives. The Habitats Directive does not preclude such an assessment from being carried out without conservation objectives specific to the SPA in question having been adopted. They argue that the main aim of Article 6(3) of the Habitats Directive is to ensure that the integrity of such sites is not adversely affected.

19The referring court is essentially uncertain whether the Habitats Directive requires conservation objectives specific to a given SPA to have been adopted in order for a national authority, when examining an application for permission for that plan or project, to be able to carry out a valid appropriate assessment of the implications of a plan or project for the site concerned.

20In those circumstances, the Court of Appeal decided to stay the proceedings and to refer the following question to the Court of Justice for a preliminary ruling:‘Are valid conservation objectives for [an SPA] a prerequisite to the competent authority’s jurisdiction to carry out a valid appropriate assessment under Article 6(3) of [the Habitats Directive] when considering an application for a grant of development consent?’

Case C‑356/25

21On 8 January 2021, Curns Energy Limited submitted an application for development consent for a wind farm and associated infrastructure. The development is to include 17 wind turbines within two clusters – 11 of which are to be located in County Waterford and 6 of which are to be located in County Cork – an underground collector cable connection of around 3.3 km in length, a substation with a loop-in connection into the Knockraha – Woodhouse 110 kilovolt (kV) line via two 40 m overhead lines and a lithium ion battery storage facility co-located with the substation. By order of 8 November 2023, the Planning Commission granted planning permission for the development at issue in the main proceedings. That development is located 9.9 km from the Blackwater Callows SPA.

22As in Case C‑27/25, it is not disputed that, at the date of adoption of that order, Ireland had not yet adopted conservation objectives specific to the SPA concerned.

23Mr Massey brought an action before the High Court seeking, first, annulment of that decision and, second, declaratory relief in the form of a declaration that the screening of the environmental implications of the development at issue in the main proceedings for the Blackwater Callows SPA should have been carried out having regard to the conservation objectives and/or conservation measures specific to that area, of which, however, there were none at the time when that order was adopted.

24That court dismissed that application for annulment. However, Mr Massey’s application for declaratory relief remains pending before it.

25The High Court is essentially uncertain whether, under the Habitats Directive, the absence of conservation objectives and/or conservation measures specific to the SPA constitutes a jurisdictional bar preventing a national authority from being able to carry out a screening of the environmental implications of the plan or project at issue for the protected site in order to determine whether it is necessary to carry out an appropriate assessment of those implications.

26In those circumstances, the High Court decided to stay the proceedings and to refer the following question to the Court of Justice for a preliminary ruling:‘Does Article 6(3) of [the Habitats Directive] as applied to [the Birds Directive] by Article 7 of the former directive have the effect that a determination by a competent authority of a Member State as to whether or not a plan or project not directly connected with or necessary to the management of any site for the purposes of [the Birds Directive] is likely to have a significant effect on any such site, either individually or in combination with other plans or projects, must be carried out by reference to conservation objectives and/or measures established for any site concerned and/or in particular for any site which is proposed to be screened out of consideration as one unlikely to be significantly so affected?’

Procedure before the Court

27By order of the President of the Court of 20 March 2025, the referring court’s request that Case C‑27/25 be determined pursuant to the expedited procedure provided for in Article 105 of the Rules of Procedure of the Court of Justice was refused, and that case was given priority over others pursuant to Article 53(3) of the Rules of Procedure.

28By decision of the President of the Court of 22 October 2025, Cases C‑27/25 and C‑356/25 were joined for the purposes of the oral part of the procedure and the judgment.

Admissibility of the request for a preliminary ruling in Case C‑356/25

29The Commission submits that the request for a preliminary ruling in Case C‑356/25 is inadmissible on the ground that the referring court has already dismissed the application for annulment of the decision at issue in the main proceedings in that case. In so far as the judgment of that court dismissing that application for annulment has acquired the force of res judicata, the dispute in the main proceedings has, it claims, been definitively settled, with the result that the question referred in that case is not only moot, but is also devoid of pertinence for the purpose of adjudicating on the substance.

30In the present case, that request for a preliminary ruling was made by the High Court in proceedings comprising two parts: one part consists, in essence, of an application for annulment of the decision at issue in the main proceedings, and the other part consists of an application for a declaration that the screening of the environmental implications of the development at issue in the main proceedings for the site concerned should have been carried out taking into account the conservation objectives and/or conservation measures specific to the Blackwater Callows SPA. It is clear from the order for reference that, although the first part of the dispute in the main proceedings has indeed been decided upon by the referring court, the second part nevertheless remains pending before it. That court states that the purpose of that dispute is not limited to the issue of the validity of the decision at issue in the main proceedings, but also covers the application for declaratory relief made by Mr Massey, on which it is yet to rule.

31In those circumstances, the dispute in the main proceedings retains its purpose, in so far as Mr Massey’s application for declaratory relief is still pending before the referring court.

32The fact that the action in the main proceedings seeks a declaratory remedy does not prevent the Court from ruling on a question referred for a preliminary ruling where the action is provided for under national law and that the question meets an objective need for the purpose of settling the dispute properly brought before the referring court (judgment of 10 December 2018, Wightman and Others, C‑621/18, EU:C:2018:999, paragraph 31 and the case-law cited).

33That is the case in the main proceedings. First, it is not disputed that an application for declaratory relief is a type of legal action for which provision is made under Irish law.

34Second, it should be borne in mind that, according to settled case-law, questions on the interpretation of EU law referred by a national court in the factual and legislative context which that court is responsible for defining, and the accuracy of which is not a matter for the Court to determine, enjoy a presumption of relevance. The Court may refuse to rule on a question referred for a preliminary ruling from a national court only where it is quite obvious that the interpretation of EU law sought bears no relation to the actual facts of the main action or its purpose, where the problem is hypothetical, or where the Court does not have before it the factual or legal material necessary to give a useful answer to the questions submitted to it (judgment of 13 May 2026, Korfin and Sempiola Invest, C‑225/25, EU:C:2026:401, paragraph 21 and the case-law cited).

35In that regard, it is clear from the order for reference that the outcome of the application for declaratory relief depends on the Court’s answer to the question referred, in that, if the Court were to answer that question in the affirmative, the referring court would have to find that the screening of the environmental implications of the development at issue in the main proceedings for the Blackwater Callows SPA should have been carried out taking into account the conservation objectives and/or conservation measures specific to that area. If the answer is in the negative, that court would then have to dismiss the application for declaratory relief.

36Therefore, it is not obvious that the interpretation of the Habitats Directive sought bears no relation to the actual facts of the main action or its purpose.

37It follows that the request for a preliminary ruling in Case C‑356/25 is admissible.

Consideration of the questions referred

38By their respective questions, which it is appropriate to examine together, the referring courts ask, in essence, whether Article 6(3) of the Habitats Directive must be interpreted as meaning that, in the absence of conservation objectives specific to the SPA concerned, a national authority can carry out, when examining an application for consent for a plan or project, valid screening and/or a valid appropriate assessment of the implications of that plan or project for the integrity of that SPA.

39In accordance with settled case-law, in order to interpret a provision of EU law, it is necessary to consider not only its wording, but also the context in which it occurs and the objectives pursued by the rules of which it is part (judgment of 23 April 2026, NOI – Blagoevgrad, C‑116/25, EU:C:2026:336, paragraph 31 and the case-law cited).

40It is also settled case-law that the determination of the meaning and scope of terms for which EU law provides no definition and in respect of which it makes no reference to the law of the Member States must be determined by reference to their usual meaning in everyday language, while account is also taken of the context in which they occur and the purposes of the rules of which they form part (judgment of 12 February 2026, Stichting Koskea, C‑490/24, EU:C:2026:89, paragraph 24).

41With regard to the wording of the provision in respect of which an interpretation is sought, Article 6(3) of the Habitats Directive provides that any plan or project not directly connected with or necessary to the management of the site but likely to have a significant effect thereon, either individually or in combination with other plans or projects, is to be subject to appropriate assessment of its implications for the site in view of the site’s conservation objectives.

42Further, Article 6(3) of the Habitats Directive specifies that, in the light of the conclusions of the assessment of the implications of a plan or project for the site concerned and subject to the provisions of Article 6(4), the competent national authorities are to agree to the plan or project only after having ascertained that it will not adversely affect the integrity of that site and, if appropriate, after having obtained the opinion of the general public.

43First, as regards the concept of ‘appropriate assessment’ within the meaning of Article 6(3) of the Habitats Directive, it must be pointed out that the provision does not define any particular method for carrying out such an assessment. Nonetheless, according to the wording of that provision, an appropriate assessment of the implications for a protected site of the plan or project must precede its approval and take into account the cumulative effects which result from the combination of that plan or project with other plans or projects in view of the site’s conservation objectives (judgment of 7 September 2004, Waddenvereniging and Vogelbeschermingsvereniging, C‑127/02, EU:C:2004:482, paragraphs 52 and 53).

44Second, it also follows from the wording of that provision that the appropriate assessment of the implications of a plan or project for a site must be carried out ‘in view of the site’s conservation objectives’.

45According to the usual meaning in everyday language of the words ‘in view of’, those words must be understood as requiring that the appropriate assessment be carried out taking into account the conservation objectives of the site concerned.

46In that regard, the Court has found that it is by taking account of the conservation objectives of a protected site that it is appropriate to determine the extent of the obligation to carry out an appropriate assessment of the implications of a plan or project for that site. In addition, the Habitats Directive requires the competent national authority to catalogue and assess all aspects of that plan or project that might affect the conservation objectives of that site before granting the development consent at issue (judgment of 17 December 2020, Commission v Greece, C‑849/19, EU:C:2020:1047, paragraph 51).

47In support of that, the Court has also found that Article 6(3) and (4) of the Habitats Directive, which also applies to SPAs pursuant to Article 7 of that directive, under which Member States must carry out an ex ante assessment and submit for prior authorisation any plans or projects likely to have a significant effect on the sites concerned, specifies that the protected site’s conservation objectives are to act as a ‘mandatory reference point’ for the appropriate assessments required (see, to that effect, judgment of 12 September 2024, Elliniki Ornithologiki Etaireia and Others, C‑66/23, EU:C:2024:733, paragraph 42).

48Additionally, the reference in Article 6(3) of the Habitats Directive to ‘the site’s’ conservation objectives indicates that those conservation objectives must be specific to each protected site.

49In that regard, the Court has held that those conservation objectives cannot be general and imprecise, but must, on the contrary, be specific and precise and must take into consideration the particular interests of the areas concerned, which assumes that they relate to the main types of natural habitat and species present in the SAC concerned which are of interest for the European Union (see, to that effect, judgments of 17 December 2020, Commission v Greece, C‑849/19, EU:C:2020:1047, paragraphs 58 and 59, and of 21 September 2023, Commission v Germany (Protection of special areas of conservation), C‑116/22, EU:C:2023:687, paragraph 107 and the case-law cited).

50Accordingly, it is apparent from the clear and unambiguous wording of Article 6(3) of the Habitats Directive that the appropriate assessment must be carried out based on the conservation objectives specific to the site concerned. If those objectives have not been determined, a valid appropriate assessment cannot be carried out, with the result that conservation objectives cannot be regarded as optional or as having to be taken into account only where they exist.

51That interpretation is supported by the legislative context of Article 6(3) of the Habitats Directive.

52First, according to the eighth recital of the Habitats Directive, it is appropriate, in each area designated, to implement the necessary measures having regard to the conservation objectives pursued. The tenth recital of that directive states that an appropriate assessment must be made of any plan or programme likely to have a significant impact on the conservation objectives of a site which has been designated or is to be designated in the future. As the Court has held previously, it is clear from the first sentence of Article 6(3) of the Habitats Directive in conjunction with the tenth recital thereof that the significant nature of the implications for a site of a plan or project not directly connected with or necessary to the management of the site is to be assessed as against the site’s conservation objectives. Furthermore, where a plan or project is likely to undermine those objectives, it must be considered likely to have a significant effect on that site (see, to that effect, judgment of 7 September 2004, Waddenvereniging and Vogelbeschermingsvereniging, C‑127/02, EU:C:2004:482, paragraphs 46 and 49).

53Having regard to the precautionary principle, in particular, such a risk is deemed to be present where it cannot be ruled out, having regard to the best scientific knowledge in the field, that the plan or project at issue might affect the conservation objectives for the protected site. The assessment of that risk must be made in the light, in particular, of the characteristics and specific environmental conditions of that site (judgment of 15 June 2023, Eco Advocacy, C‑721/21, EU:C:2023:477, paragraph 37 and the case-law cited).

54It follows that the requirement to carry out the appropriate assessment required in view of the conservation objectives of the protected site is not purely formal. That requirement is in fact inherent in the very nature of such an assessment, the purpose of which is precisely to determine whether the plan or project concerned is likely adversely to affect the integrity of that site, which can be assessed only in the light of the conservation objectives specific to that site.

55In that regard, the Court has found that the assessment to be carried out under Article 6(3) of the Habitats Directive may not have lacunae and must contain complete, precise and definitive findings and conclusions capable of removing all reasonable scientific doubt as to the effects of the proposed works that are envisaged on the protected site concerned (judgment of 15 June 2023, Eco Advocacy, C‑721/21, EU:C:2023:477, paragraph 39 and the case-law cited). Therefore, where specific conservation objectives have not been set prior to the completion of the requisite appropriate assessment, it cannot be found that such an appropriate assessment satisfies those requirements that the findings and conclusions be complete, precise and definitive.

56Second, the Court has held that the obligations relating to the management of SPAs provided for by Article 4 of the Birds Directive, read in the light of Article 6 of the Habitats Directive, involve the Member States setting conservation objectives for those areas. The Court has found that the legal regime governing an SPA must include such conservation objectives (see, to that effect, judgment of 12 September 2024, Elliniki Ornithologiki Etaireia and Others, C‑66/23, EU:C:2024:733, paragraph 46).

57The Court has also found that Article 4(1) and (2) of the Birds Directive and Article 6(2) to (4) of the Habitats Directive must be interpreted as requiring Member States to establish, for each SPA, individual conservation objectives and conservation measures for all protected species and their habitat. In doing so, Member States are responsible for defining priorities according to the significance of those measures for achieving conservation objectives in respect of all those species (judgment of 12 September 2024, Elliniki Ornithologiki Etaireia and Others, C‑66/23, EU:C:2024:733, paragraph 59).

58In that regard, Article 4(4) of the Habitats Directive requires the competent authorities of the Member State concerned, when designating the SAC, to establish priorities in the light of the importance of the sites for the maintenance or restoration, at a favourable conservation status, of a certain natural habitat type or a certain species as well as for the coherence of the Natura 2000 network, and according to the threats of degradation or destruction to those sites. Establishing those priorities implies that those conservation objectives must necessarily have been set beforehand (judgment of 17 December 2020, Commission v Greece, C‑849/19, EU:C:2020:1047, paragraph 46).

59Consequently, the determination of those conservation objectives is a necessary prerequisite for the establishment of conservation priorities and measures (judgment of 29 June 2023, Commission v Ireland (Protection of special areas of conservation), C‑444/21, EU:C:2023:524, paragraph 156 and the case-law cited).

60It follows from the foregoing that the conservation objectives, which are to be established beforehand and are specific to each protected site, set the framework both for defining the conservation measures applicable to a protected site and for defining priorities as regards the protection of species and of that site, and how the appropriate assessment of the implications for such a site of plans and projects is to be conducted.

61Accordingly, determining those conservation objectives constitutes a preliminary stage that is essential for the implementation of the assessment procedure provided for in Article 6(3) of the Habitats Directive.

62That interpretation is not called into question by the fact, relied on by Ireland, that, under Article 4(4) of that directive, Member States have a period of six years within which to designate SACs.

63It is true that the process for designating SACs takes place in three stages provided for in Article 4 of the Habitats Directive: the proposal by each Member State of a list of sites, the establishment by the Commission of a list of sites of Community importance, and then the formal designation of those sites as SACs within a period of six years at most, establishing the necessary conservation priorities and measures (see, to that effect, judgment of 12 June 2019, CFE, C‑43/18, EU:C:2019:483, paragraph 37).

64However, the Birds Directive, which is applicable to the SPA at issue in the main proceedings, does not contain any equivalent provision laying down such a period for SPAs. The rules for designating SACs and SPAs respectively are structurally distinct, notwithstanding the fact that they pursue common objectives within the Natura 2000 network. Therefore, by virtue of the reference made in Article 7 of the Habitats Directive, the obligations arising under Article 6(2), (3) and (4) of that directive are to replace any obligations arising under Article 4(4) of the Birds Directive and apply to SPAs as soon as they are classified as such by the Member States.

65In any event, it is apparent from the documents before the Court that Blackwater Callows was designated as an SPA within the meaning of the Birds Directive in 2010. It is common ground that, on the date on which the decisions at issue in the main proceedings were adopted, in 2022 and 2023 respectively, Ireland had not adopted conservation objectives specific to that area.

66In that regard, it should be recalled that the failure of a Member State to adopt specific and precise conservation objectives for sites coming within the Natura 2000 network constitutes a failure to fulfil its obligations under Article 4(4) of the Habitats Directive (judgment of 29 June 2023, Commission v Ireland (Protection of special areas of conservation), C‑444/21, EU:C:2023:524, paragraph 158 and the case-law cited). As is apparent from paragraph 64 of the present judgment, those obligations also apply to SPAs as soon as they are classified as such by the Member States.

67The interpretation of Article 6(3) of the Habitats Directive set out in paragraphs 60 and 61 of the present judgment is also borne out by the objectives pursued by that directive.

68As is apparent from the first subparagraph of Article 3(1) of the Habitats Directive, the very structure of the Natura 2000 network involves each site performing a specific function there, with the result that it contributes to the overall coherence of that network and, therefore, to the achievement of the general objective of ensuring a favourable conservation status for all the species and habitat types listed in Annexes I and II to the Habitats Directive.

69That general objective is given concrete expression vis-à-vis protected sites through the establishment of conservation objectives defining the status to be achieved for those species and habitat types within the sites concerned. In that regard, the Court has underscored the importance of preserving the sites concerned at a favourable conservation status, which entails the lasting preservation of the constitutive characteristics of the site concerned that are connected to the presence of a natural habitat type or species whose preservation was the objective justifying the designation of that site in the list of sites of Community importance, in accordance with that directive (see, to that effect, judgment of 24 June 2021, Commission v Spain (Deterioration of the Doñana natural area), C‑559/19, EU:C:2021:512, paragraph 166 and the case-law cited).

70Accordingly, the defining of the conservation measures applicable to a protected site and the defining of priorities as regards the protection of protected species and sites, and how the appropriate assessment of the implications of plans and projects is to be conducted for such a site are the specific actions and mechanisms to be put in place with the aim of attaining the conservation objectives set for the site concerned.

71The specificity and precision of the conservation objectives set by the Member State concerned therefore make it possible to verify whether the conservation measures based on those objectives are appropriate for attaining the desired conservation status of the site in question (see, to that effect, judgment of 21 September 2023, Commission v Germany (Protection of special areas of conservation), C‑116/22, EU:C:2023:687, paragraphs 115 and 116). The same applies to the conduct of the appropriate assessment of the implications of plans and projects for a protected site.

72In the absence of conservation objectives that have been established beforehand and are specific to the site concerned, the appropriate assessment which the national authorities must carry out is necessarily based on an insufficiently precise and complete basis, as has been noted in paragraph 55 of the present judgment, which has the effect of increasing the risk that plans or projects not directly connected with or necessary to the management of that site, but adversely affecting its integrity, may be authorised by those national authorities, thereby causing significant, or even irreparable, ecological damage to that site.

73The absence of those objectives would, moreover, deprive the appropriate assessment procedure of the foreseeability and legal certainty that are necessary for it to be implemented in conditions appropriate to ensuring that the objectives pursued by the Habitats and Birds Directives are attained. In that regard, the Court notes that the obligations on Member States under Article 6 of the Habitats Directive must be implemented effectively and by complete, clear and precise measures (judgment of 12 September 2024, Elliniki Ornithologiki Etaireia and Others, C‑66/23, EU:C:2024:733, paragraph 56 and the case-law cited).

74Therefore, an appropriate assessment of the implications of a plan or project for a protected site conducted without the conservation objectives specific to that site having been adopted beforehand risks compromising the objectives pursued by Article 6(3) of the Habitats Directive and, ultimately, the objectives of that directive itself.

75It follows from all the foregoing considerations that the prior adoption, by the competent national authorities, of conservation objectives specific to the site concerned is a condition that must be satisfied in order for the appropriate assessment required under Article 6(3) of the Habitats Directive to be lawful.

76As regards the stage involving the screening of the environmental impact of the plan or project at issue on the protected site, which is the subject of the question referred for a preliminary ruling in Case C‑356/25, the Court notes that that stage is a preliminary stage intended to determine whether it is necessary to carry out, subsequently, an appropriate assessment of the implications of that plan or project for the site concerned (see, to that effect, judgment of 12 April 2018, People Over Wind and Sweetman, C‑323/17, EU:C:2018:244, paragraph 40).

77In that regard, Article 6(3) of the Habitats Directive sets out clearly that the obligation to carry out such an assessment is dependent on both of the following conditions being met: the plan or project in question must not be connected with or necessary to the management of the site concerned and it must be likely to have a significant effect on the site (judgment of 12 April 2018, People Over Wind and Sweetman, C‑323/17, EU:C:2018:244, paragraph 32).

78The screening stage, as a preliminary step to determine whether it is necessary to carry out an appropriate assessment, is specifically intended to determine whether those conditions are satisfied.

79That screening stage does not involve carrying out an analysis as full and precise as the analysis which must be carried out in the context of the appropriate assessment of the implications of a plan or project for the site concerned. The Court has held that the analysis of measures capable of avoiding or reducing any significant effects on the site concerned must be carried out not at the screening stage, but at the appropriate assessment stage. According to the Court, taking account of such measures at that screening stage would be liable to compromise the practical effect of the Habitats Directive generally and the appropriate assessment in particular, as the latter stage would be deprived of its purpose and there would be a risk of circumvention of that stage, which constitutes, however, an essential safeguard provided for by the directive (see, to that effect, judgment of 15 June 2023, Eco Advocacy, C‑721/21, EU:C:2023:477, paragraphs 46 and 47 and the case-law cited).

80As regards the first of the conditions referred to in paragraph 77 of the present judgment, the issue of whether the plan or project at issue is directly connected with or necessary to the management of the site concerned clearly relates to the characteristics of that plan or project considered in itself. It follows that the adoption of conservation objectives specific to the protected site cannot be regarded as indispensable in that regard.

81As regards the second of those conditions, it involves, inter alia, cataloguing the protected sites which might be affected by the plan or project in question, taking account of the potential effects of that plan or project. It may be possible to carry out such cataloguing without it being necessary to take into account the conservation objectives specific to each of the protected sites. That may be the case where the delimitation of the geographical area which the plan or project is likely to affect makes it possible to rule out – with the certainty required in accordance with the precautionary principle, on the basis of objective criteria, such as the distance between that plan or project and the protected sites and the existence or absence of plausible impact pathways – any risk of certain protected sites being affected, irrespective of the conservation objectives specific to those sites.

82By contrast, as regards protected sites within the geographical area likely to be affected by that plan or project, the assessment of the probability or risk that that plan or project will have a significant effect on those sites cannot be carried out without taking account of the conservation objectives specific to those sites. The Court notes in that regard that, as is apparent from paragraphs 76 to 79 of the present judgment, that assessment does not involve carrying out as complete and precise an analysis of the implications of the plan or project concerned for the protected site as the appropriate assessment itself, but rather an assessment of whether, taking account of the conservation objectives specific to that site, the probability or risk that that plan or project will have a significant effect on it may or may not be ruled out.

83In the light of the foregoing, the Court holds that, in the context of the screening phase, it may be possible to delimit the geographical area likely to be affected by a plan or project without it being necessary to take into account the conservation objectives specific to each of the protected sites. By contrast, the assessment of the probability or risk of such a plan or project having a significant effect on a protected site within that geographical area cannot be carried out without taking account of the conservation objectives specific to that site.

84In the light of all the foregoing considerations, the answer to the questions referred is that Article 6(3) of the Habitats Directive must be interpreted as meaning that, where conservation objectives specific to the SPA concerned have not been adopted beforehand, a national authority cannot carry out a valid appropriate assessment of the implications of a plan or project for the integrity of that area, in the context of the examination of an application for consent for that plan or project. In the context of the screening phase, it may be possible to delimit the geographical area likely to be affected by a plan or project without it being necessary to take into account the conservation objectives specific to each of the protected sites. By contrast, the assessment of the probability or risk of such a plan or project having a significant effect on a protected site within that geographical area cannot be carried out without taking account of the conservation objectives specific to that site.

Limitation of the temporal effects of the present judgment

85At the hearing, Ireland requested the Court to limit the temporal effects of the present judgment.

86In that regard, it should be recalled that the interpretation which, in the exercise of the jurisdiction conferred on it by Article 267 TFEU, the Court gives to rules of EU law clarifies and defines the meaning and scope of those rules as they must be or ought to have been understood and applied from the time of their entry into force. It is only exceptionally that the Court may, in application of the general principle of legal certainty inherent in the EU legal order, be moved to restrict for any person concerned the opportunity of relying on a provision which it has interpreted with a view to calling into question legal relationships established in good faith. Two essential criteria must be fulfilled before such a limitation can be imposed, namely that those concerned should have acted in good faith and that there should be a risk of serious difficulties, with those criteria being cumulative (judgment of 19 March 2026, DB InfraGO and DB RegioNetz Infrastruktur, C‑770/24, EU:C:2026:218, paragraph 61 and the case-law cited).

87Accordingly, the Court has taken that step only in quite specific circumstances, notably where there was a risk of serious economic repercussions owing in particular to the large number of legal relationships entered into in good faith on the basis of rules considered to be validly in force and where it appeared that individuals and national authorities had been led to adopt practices which did not comply with EU law by reason of objective, significant uncertainty regarding the implications of provisions of EU law (judgment of 19 March 2026, DB InfraGO and DB RegioNetz Infrastruktur, C‑770/24, EU:C:2026:218, paragraph 62 and the case-law cited).

88In the present case, it does not appear that Ireland has demonstrated a risk of serious difficulties. On the contrary, given that that Member State ultimately adopted, in 2024, conservation objectives specific to all SPAs located in its territory and that, in accordance with the principle of legal certainty, EU law does not require that administrative bodies be placed under an obligation, in principle, to reopen an administrative decision which has become final upon expiry of reasonable periods for legal remedies or by the exhaustion of remedies (judgment of 19 March 2026, DB InfraGO and DB RegioNetz Infrastruktur, C‑770/24, EU:C:2026:218, paragraph 65 and the case-law cited), such a risk appears to have been ruled out.

89Since the second criterion referred to in paragraph 86 above is not satisfied, it is not necessary to ascertain whether the criterion relating to the good faith of those concerned is satisfied.

90It follows from the foregoing that it is not appropriate to limit the temporal effects of the present judgment.

Costs

91Since these proceedings are, for the parties to the main proceedings, a step in the action pending before the referring court, the decision on costs is a matter for that court. Costs incurred in submitting observations to the Court, other than the costs of those parties, are not recoverable.

Operative part

On those grounds, the Court (Fourth Chamber) hereby rules: Article 6(3) of Council Directive 92/43/EEC of 21 May 1992 on the conservation of natural habitats and of wild fauna and floramust be interpreted as meaning that where conservation objectives specific to the special protection area concerned have not been adopted beforehand, a national authority cannot carry out a valid appropriate assessment of the implications of a plan or project for the integrity of that area, in the context of the examination of an application for consent for that plan or project. In the context of the screening phase, it may be possible to delimit the geographical area likely to be affected by a plan or project without it being necessary to take into account the conservation objectives specific to each of the protected sites. By contrast, the assessment of the probability or risk of such a plan or project having a significant effect on a protected site within that geographical area cannot be carried out without taking account of the conservation objectives specific to that site.

Delivered in open court in Luxembourg on 16 July 2026.