In July 2025, the European Court of Human Rights issued a landmark ruling for Belgian property owners. In the case of Wulffaert v. Belgium, the Court held that if planning regulations are relaxed after works are carried out, the original violation loses its legal classification. A principle that could benefit many property owners across all three regions.
What does the ECHR ruling Wulffaert v. Belgium of 10 July 2025 say?
The ruling Wulffaert and Wulffaert Beheer NV v. Belgium (ECHR, 10 July 2025) establishes that the most advantageous regulation for a property owner prosecuted for a planning violation must apply, including if that more favourable regulation was adopted after the facts. In other words: if you carried out works without a permit, and those same works are now exempt from a permit, you can no longer be prosecuted or convicted for that violation.
This principle, known in criminal law as lex mitior ("the more lenient law"), now applies to Belgian planning law by virtue of Article 7 of the European Convention on Human Rights.
The facts: a garden, some works, and three levels of jurisdiction
The property owner's situation
A Flemish property owner had carried out garden landscaping works without obtaining the planning permit required by the regulations in force at the time. The works — a pergola, paving, landscaping — were ordinary and nothing exceptional.
The regulatory relaxation
After the works were carried out, the Flemish planning regulations were amended. The new regulatory framework specifically exempted exactly that type of work from planning permission. What the property owner had done in a non-compliant manner at the time had become entirely legal, without even needing a permit.
Conviction by the Belgian courts
Despite this regulatory relaxation, the Belgian courts convicted the property owner at every level:
- First instance: conviction based on the original regulations
- Appeal: conviction upheld
- Court of Cassation: appeal rejected
The reasoning of the Belgian courts was orthodox: the applicable law is the one in force at the time of the facts, not the one in force at the time of judgment or thereafter.
The ECHR's decision
The European Court held that this approach violated Article 7 of the Convention, which protects against convictions for acts that did not constitute a violation at the time they were committed — and, by extension through the lex mitior principle, against convictions for acts that no longer constitute a violation at the time of judgment.
Belgium was found to have violated Article 7 of the ECHR.
Why this ruling matters for Belgian property owners
Planning relaxations are widespread
All three Belgian regions have adopted, over the years, significant relaxations to their planning regulations. These amendments were generally aimed at simplifying administration by exempting routine works from planning permission when they have no major impact on the built environment or on neighbours.
In the Flemish Region, the system of "exempt works" (vrijgestelde handelingen) has been considerably broadened in recent years.
In the Walloon Region, the Code of Territorial Development (CoDT) provides categories of works exempt from planning permission, the list of which was extended in 2019 and 2023.
In the Brussels Region, the Government's decree on exempt acts and works has been amended several times to broaden exemptions.
Types of works affected
The Wulffaert ruling is particularly relevant for works that have experienced a favourable regulatory evolution:
| Type of works | Common evolution | Potential impact |
|---|---|---|
| Garden landscaping (pergola, paving, garden shed) | Progressive exemption | Ruling directly applicable |
| Loft/attic conversion | Expanded exemptions in certain areas | To be checked region by region |
| Conservatories and light extensions | Recent relaxations | Depending on size and zone |
| Minor changes of use | Progressive simplifications | Varies by region |
| Aerials and technical installations | Extended exemptions | Depending on type and size |
A common "violation then exemption" pattern
In practice, many works went through a "violation" period (2005–2015, for example) followed by an "exempt" period (2016 to date). Property owners convicted or threatened with conviction during the violation period may find themselves in the same situation as the Wulffaert property owner.
The limits of the ruling: what it does not cover
It is important not to over-interpret this ruling. The lex mitior principle does not apply in all situations.
What the ruling does not cover
Works still subject to a permit: if the works you carried out without a permit remain subject to a permit today, the Wulffaert ruling does not protect you. The exemption must cover exactly the type of works in question.
Regularised works: if you have already obtained a regularisation permit, the situation is resolved by that permit. The ruling does not change your situation.
Violations with ongoing material impact: the ruling concerns the criminal classification of the violation, not the rights of third parties (neighbours, municipalities). Third-party claims based on grounds other than the planning violation may subsist.
Imposed regularisations: in certain cases, authorities may still require remediation or reinstatement works, independently of the criminal question.
What property owners and managers should do
Identify affected properties
If you manage older properties, particularly detached houses or buildings with modifications dating from the 2000s–2015 period, now is the time to check whether any works were carried out without a permit and whether those same works are now exempt.
Questions to ask for each property:
- Were any works carried out without a permit?
- Are those works now exempt from a permit in the relevant region?
- Is there an ongoing proceeding or threat of prosecution?
Consult a specialist lawyer
The practical application of the Wulffaert ruling requires a case-by-case analysis. Not all unauthorised works automatically benefit from lex mitior protection. A lawyer specialising in planning law can assess whether your situation is covered by the ECHR case law.
Document the applicable regulations
Whether you are at risk or simply being prudent, keep a record of the regulations applicable to the works carried out: the regulatory texts in force at the time of the facts, the current texts, and if possible an explicit legal note on the applicable exemptions.
For ongoing proceedings
If a planning proceeding is underway against you or one of your clients for works potentially covered by the Wulffaert ruling, bring this case law to your lawyer's attention immediately. The ruling of 10 July 2025 is recent and some courts may not yet have integrated its implications into their reasoning.
Case law to watch
The Wulffaert ruling opens up an important area of case law development. Belgian courts will need to adapt their approach to planning disputes to incorporate the lex mitior principle as interpreted by the ECHR. The first Belgian "post-Wulffaert" rulings will show the practical scope of this protection.
For property managers, this is a topic to monitor closely — particularly if properties in the portfolio were the subject of historic works whose regulatory status has since evolved.
With Seido, document every job on a property, including regulatory aspects: permits obtained, works carried out, date and nature of the jobs. In a planning dispute, this timestamped documentation can be decisive. Discover Seido →
This article is part of Property Essentials #1 — January 2026. Also read: EPC in Brussels: co-owners soon jointly liable for energy-inefficient buildings.
Sources and references
- Wulffaert and Wulffaert Beheer NV v. Belgium, ECHR, 10 July 2025 — violation of Article 7 ECHR (lex mitior)
- EHRM veroordeelt Belgie voor schending artikel 7 EVRM bij toepassing vrijstellingsbesluit, Aurius Advocaten, July 2025
- Full text of the ruling: HUDOC (search "Wulffaert Belgium")
- Article 7 of the European Convention on Human Rights (ECHR)