The Walloon decree of 25 April 2024 "amending various decrees concerning the environment" brings about a profound reform of the legal system for environmental permits, which will have implications for wind energy projects among other things.
After an appeal for partial annulment of this decree was filed, the Constitutional Court upheld the main components of this reform in its judgment no. 53/2026 of 23 April 2026.
Currently applicable regulation – limited validity period of environmental permits
The decree of 25 April 2024 has not yet come into force, as the date of entry into force still needs to be determined by the Walloon government. Therefore, the previous regulation still applies.
Under the currently applicable regulation, an environmental permit is generally granted for a maximum duration of twenty years, which is extended to thirty years when it concerns a wind energy project.
The urban planning aspect of the unique permit, on the other hand, is generally granted for an indefinite duration, unless the government limits its duration based on article D.IV.80 of the Walloon Code of Spatial Planning (“CoDT”) (for example, in the case of the placement of wind turbines in an area not designated for urbanisation).
Approval of the decree of 25 April 2024 and new regulation applicable to the environmental permit
From now on, the environmental permit will in principle be granted for the duration of the operation of the facility, and no longer for a specific duration as provided in the currently applicable regulation.
This evolution is accompanied by the introduction of a mechanism for periodic updating (i.e. every twenty years) of the specific operating conditions of the permit.
The updating mechanism is initiated by the government: before the expiry of the twenty-year term, the technical officer informs the operator that they must submit a request for updating if they wish to continue their activity. The operator must confirm receipt of this notification and submit their request within the required deadlines; otherwise, the permit may lapse.
The purpose of the updating is to adapt the operating conditions to current environmental standards and challenges, without calling into question the principle of a permit that is valid for the entire duration of the operation.
Unique permits – alignment of the duration of the environmental component with that of the urban planning component
In certain cases, the duration of the environmental permit is aligned with that of the urban planning component of the unique permit: when the urban planning component is granted for a limited duration based on article D.IV.80 of the Walloon Code of Spatial Development (“CoDT”), the environmental permit is indeed granted for the same duration.
When the urban planning aspect of the unique permit is granted for an indefinite period (which remains the principle), the environmental permit is granted for the duration of the operation.
Regulation applicable to existing valid permits
The decree of 25 April 2024 introduces a transitional arrangement that applies to existing permits.
Permits that are valid at the time of the entry into force of the decree are deemed to have been granted for the duration of the operation of the establishment concerning the 'environmental permit' aspect. They therefore do not need to be renewed upon expiry, but will be subject to the procedure for periodic updating of the specific operating conditions.
A specific transitional arrangement is provided for existing permits for wind turbines. As with the other existing permits, concerning the environmental aspect, the permits for wind turbines that are valid at the time of the entry into force of the decree are deemed to have been granted for the duration of the operation of the establishment.
Regarding the urban planning aspect, however, the existing permits for wind turbines are deemed to have been granted for an indefinite period, thereby nullifying the time limits that would have been imposed under the previous regulation.
This choice is in line with the previous regulation, which already recognised the economic and technical specificity of wind energy projects.
Ratification by the Constitutional Court of the regulation applicable to wind energy projects
The Constitutional Court rules in its judgment of 23 April 2026 that the specific regulation applicable to wind energy projects does not violate either the principle of equality and non-discrimination or the right to a healthy environment, as guaranteed by Article 23 of the Constitution.
The Constitutional Court notably observes that there were already differences in treatment regarding wind energy projects in the previous regulation, that these differences are related to the significant investments required for wind energy projects and the lifespan of the installations, and that they align with the European guidelines aimed at promoting projects in the field of renewable energy.
This judgment provides a useful clarification that strengthens the legal certainty of the framework for wind energy projects in Wallonia.
Usefulness of the reform in light of the pursued objectives
The reform implemented by the decree of 25 April 2024 aims for administrative simplification and strengthening of legal certainty for operators.
By replacing the logic of the periodic extension of the environmental permit with a permitting system that is valid for the duration of the operation (in combination with a mechanism for updating the operating conditions), the Walloon legislator aimed to reconcile the stability of the permits with the evolution of environmental standards and challenges.
In practice, however, this reform will not necessarily lead to more predictability for the operators. Just like with a permit application, the updating of the operating conditions can indeed be subjected to thorough scrutiny – and can be refused by the competent authority if the operating conditions no longer meet the applicable legal and regulatory requirements.
Such a refusal has the same consequences as a non-renewal of the permit, as the government is then authorised to set a date on which the operation must be terminated.
Practice will show whether this reform actually provides more certainty and stability.