By way of Article 5 of the Flemish Decree of 19 April 2024 amending the Decree of 25 April 2014 on environmental permits, the Flemish legislature introduced a provision enabling the municipal executive (college of mayor and aldermen) or provincial executive (deputation) to decide on permit applications in the first administrative instance in respect of projects for which the executive itself acted as both developer and permit applicant, provided that such projects were solely subject to an environmental impact assessment (EIA) screening — as opposed to a full environmental impact assessment. The Constitutional Court has now annulled that provision in its judgment of 18 September 2025 (no. 122/2025).

The judgment of 18 September 2025 is the latest development in a legal saga originating in 2022. The proceedings trace back to the so-called 'Laundry ruling' ('Wasserijsite-arrest') of the Council for Permit Disputes of 6 October 2022. Cassation proceedings were subsequently brought before the Council of State, which in turn referred a question to the Court of Justice of the European Union (CJEU) for a preliminary ruling. The key question: is a municipal or provincial executive permitted to determine whether one of its own projects is subject only to an EIA screening — or whether EU law requires that function to be performed by a body with genuine autonomy from the developer?

In its judgment of 8 May 2025 (Case C-236/24), the CJEU interpreted the EIA Directive (Article 9a of Directive 2011/92/EU, as amended by Directive 2014/52/EU). The Court held that where the authority competent to determine whether a project is subject to an environmental impact assessment is itself the developer of that project, Member States must ensure an appropriate separation between conflicting functions when carrying out that assessment. Importantly, the Court clarified that this obligation is not confined to full EIA procedures but extends equally to the screening stage — i.e., the preliminary determination of whether a full EIA is required. Such separation must be organised so that the internal administrative entity performing the screening possesses genuine autonomy, including its own dedicated administrative and human resources.

Drawing on the CJEU's judgment, the Constitutional Court held that the provision as enacted by the Flemish legislature failed to ensure the required level of genuine autonomy. Although municipal and provincial environmental officials are appointed by the elected municipal or provincial council and are statutorily required to exercise their functions with complete independence and neutrality, the Constitutional Court found these elements to be insufficient. The Decree of 25 April 2014 did not provide the structural and organisational guarantees necessary to ensure that environmental officials can systematically assess the EIA screening note with the required objectivity, given that their appointing authority is itself the developer and permit applicant.

On that basis, the Constitutional Court annulled Article 5 of the Decree of 19 April 2024 as incompatible with Articles 10 and 11 of the Belgian Constitution, read in conjunction with Article 9a of the EIA Directive.

Various projects that were granted a permit based on this regulation therefore were jeopardised.

The Constitutional Court declined to maintain the legal effects of the annulled provision.

Under Belgian constitutional law, the Court may decide to preserve the effects of an annulled provision in order to prevent legal uncertainty; however, in the present case, it found no plausible basis for concluding that the retroactive effect of the annulment would entail a high degree of legal uncertainty — notably in view of the limited material and temporal scope of the annulled provision. The annulment therefore operates with full retroactive effect from the date of entry into force of the annulled article.

This does not, however, mean that permits already granted automatically cease to exist. The Constitutional Court expressly noted that the Council for Permit Disputes retains the power — distinct from the Constitutional Court's own power to maintain effects — to uphold the legal consequences of an individual environmental permit that was granted on the basis of the now-annulled provision.

As a result of the ruling of the Constitutional Court, a legislative initiative of the Flemish legislator was required to resolve this illegality.

The Department of Environment examined the judgment and made clear on its website what temporary arrangements should apply until a solution was found.

In response, the Flemish Parliament has taken action and adopted a new Act: the Act of 21 November 2025 amending the Act of 25 April 2014 on the environmental permit, with regard to the prevention of conflicts of interest in cases where an environmental permit is applied for by a municipality or province.

The Flemish Parliament has opted for a straightforward upward transfer of competence. In concrete terms, this means that all municipal cases involving an environmental impact assessment or a project-EIA-screening shall be transferred to the Provincial Deputation. Provincial cases of this nature shall henceforth be transferred to the Government of Flanders. This transfer of competence also applies when the Board of Mayor and Aldermen or the Provincial Deputation is (de facto) one of the applicants for the project.

The Flemish Parliament also provides clarity on the temporal application of this amendment. In previous publications, we have pointed out the interim approach recommended by the Department of Environment following the annulling judgment, namely the ex officio upward transfer of competence. Although this approach was consistent with European regulations and served to prevent conflicts of interest, it remained legally vulnerable for as long as it was not anchored in a Flemish Act of Parliament. For that reason, the legislature has opted for retroactive effect of the amendment as from 19 September 2025, mainly in order to prevent legal uncertainty.

The amended Act accordingly clarifies the impact of the Constitutional Court’s judgment and identifies which decisions are affected:

  • Existing permits

The annulling judgment affects the legality of permits granted in application of the annulled provision (article 15/1 of the Environmental Permit Act of 25 April 2014). Those permits will continue to exist and will not be invalidated by operation of law, but they are vitiated by a procedural defect.

  • New appeal periods

Article 18 of the Special Act on the Constitutional Court provides that a new appeal period of six months commences from the date pf publication of the annulling judgment in the Belgian Official Gazette, i.e. on 14 October 2025. For permits that are based (in whole or in part) on the annulled provision, this additional appeal period may apply. This means that a new administrative or judicial appeal may be lodged within six months against decisions taken between 20 May 2024 and 14 October 2025.

The Public Law team at Monard Law will be happy to assist you with all your questions regarding the recent judgment and its impact, along with any other questions concerning environmental law.