On 16 July 2026, the Court of Justice of the European Union (Court) handed down judgment in joined cases C-27/25 – Knocknamona and C-356/25 – Massey (judgment). The Court concluded that where conservation objectives specific to the special protection area have not been adopted beforehand, a national authority cannot carry out a valid appropriate assessment (AA) of the implications of a plan or project for the integrity of that area, in the context 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 having to take into account the conservation objectives specific to each protected site. However, the assessment of the probability or risk that such a plan or project will have a significant effect on a protected site within that geographical area cannot be carried out without taking into account the conservation objectives specific to that site.

As we previously reported, the Opinion of Advocate General Kokott, delivered on 16 April 2026, concluded that the setting of site-specific conservation objectives (SSCOs) is not a prerequisite for AA and AA screening. The Court rejected this conclusion.

The Court also concluded that it is not appropriate to limit the temporal effects of the judgment.

In Knocknamona, An Bord Pleanála (Board), as it then was, granted planning permission to Knocknamona Windfarm Limited for amendments to a previously permitted wind farm in Co. Waterford, permitting an increase in the uppermost tip height of the turbines and a meteorological mast. In considering the application for development consent, the Board carried out an AA for five protected sites, including the Blackwater Callows SPA, for which, at the time of the decision, Ireland had not yet set specific conservation objectives. Following judicial review proceedings taken by SU and Wild Ireland Defence, and a resulting request for a preliminary ruling by the Court of Appeal to the Court on whether valid conservation objectives for a SPA are a prerequisite to the competent authority’s jurisdiction to carry out a valid AA under Article 6(3) of the Habitats Directive when considering an application for a grant of development consent, the case was joined with Massey on similar principles of law.

The Judgment

The Court, addressing 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 valid AA and/or AA screening when examining an application for consent for a plan or project, found:

• Determining Conservation Objectives ‘Essential’ for Implementation of AA: Determining conservation objectives is an essential preliminary step in implementing the AA procedure. The wording of Article 6(3) of the Habitats Directive is “clear and unambiguous”: AA must be based on the conservation objectives specific to the site concerned. If such objectives have not been determined, a valid AA cannot be carried out. Accordingly, conservation objectives cannot be considered optional or factored in only where they exist.
• AA Must Contain ‘Complete’, ‘Precise’ and ‘Definitive’ Findings: where conservation objectives specific to the site concerned have not been established beforehand, the AA which the national authorities must carry out is based on an insufficiently precise and complete basis, which increases the risk that plans or projects adversely affecting its integrity, may be authorised by the national authorities, causing “significant, or even irreparable, ecological damage” to that site.
• AA Screening: It may be possible to delimit the geographical area likely to be affected by a plan or project without having to take into account the conservation objectives specific to each protected site. For example, where there is no “pathway” for impacts to the SPA. However, the assessment of the probability or risk that such a plan or project will have a significant effect on a protected site within that geographical area cannot be carried out without taking into account the conservation objectives specific to that site.
• Temporal Limitation: part of the essential criteria for the granting of a temporal limitation, which the Court has taken only in “quite specific circumstances”, is that there should be a risk of “serious difficulties”. As Ireland had not demonstrated a risk of serious difficulties, given that it adopted conservation objectives specific to all SPAs in its territory in 2024, it is “not appropriate” to limit the temporal effects of the judgment.

Conclusion

The Court, in interpreting Article 6(3) of the Habitats Directive and in a marked departure from the Opinion of AG Kokott, has delivered a clear and authoritative ruling; where conservation objectives specific to the SPA concerned have not been adopted beforehand, in the context of an application for consent for that plan or project, a lawful AA cannot be carried out. However, it may be possible to carry out AA screening in certain circumstances.

While the practical implications of the judgment remain to be seen, many projects will be unaffected given the recent adoption of SSCOs for a large number of European Sites. However, there will likely be considerable focus in the coming weeks on how regulators and decision-makers across the EU navigate the practical consequences of this ruling.

For further information, please contact Jason Milne, Michelle Martin, or your usual William Fry contact.

Contributed by Nessa Boland