Brussels Court Orders Climate-Driven Moratorium on Large Urban Development Projects

On 29 October 2025, the Brussels Tribunal of First Instance (the “Court”) delivered a groundbreaking judgment ordering the Brussels-Capital Region (“RBC”) to implement a moratorium on urbanization and impermeabilization of undeveloped sites exceeding 0.5 hectares. The moratorium must remain in effect until adoption of the revised Regional Land Use Plan (“PRAS”) or 31 December 2026, whichever occurs first. The Court found that the RBC had breached its general duty of care by failing to adequately protect natural carbon sinks and continuing to authorize development that reduces the territory's greenhouse gas absorption capacity. 

While this judgment represents a significant victory for environmental protection, it creates substantial legal uncertainties for the real estate sector. Key uncertainties include: (i) the judgment’s scope of application to existing permits, (ii) the specific implementation mechanisms the RBC will adopt, and (iii) the treatment of sites where construction has already commenced. Developers should immediately assess their project portfolios for exposure to the moratorium and engage with regional authorities to clarify implementation measures.

The Matter and Legal Proceedings

In a landmark environmental judgment delivered on 29 October 2025, the Court ruled in favour of environmental associations We Are Nature.Brussels and Bruxelles Nature, along with numerous individual plaintiffs, in their climate action against the RBC. The case centered on the RBC's alleged failure to adequately protect and enhance natural carbon sinks on its territory, particularly in the context of ongoing urbanization and soil sealing.

The plaintiffs argued that the RBC had breached its general duty of care under Articles 1382 and 1383 of the former Civil Code by failing to take necessary measures to prevent the harmful consequences of climate change on the living conditions of Brussels residents. Specifically, they challenged: (i) the RBC's inadequate management of natural greenhouse gas absorption sinks, and (ii) its continued authorization of urbanization projects that further reduce the territory's carbon absorption capacity.

Court's Reasoning and Findings

The Court found that the RBC had indeed failed to act with due prudence and diligence. The Court based its analysis on four key findings:

• First, the Court noted that the RBC had previously been found liable for failing to meet minimum greenhouse gas emission reduction requirements between 2013 and 2020, as established in earlier climate litigation. The Brussels Court of Appeal had already determined that the RBC's climate policies during this period were insufficient to meet scientific climate targets and violated Articles 2 and 8 of the European Convention on Human Rights.
• Second, the Court found that the RBC lacks any updated assessment of the regional capacity for greenhouse gas absorption by natural sinks. The RBC admitted that no current inventory exists for carbon capture capacity by natural sinks at the regional level, with the most recent estimate from 2019 showing that natural spaces absorbed only 10 kt CO2 equivalent compared to direct regional emissions of 3,705 kt CO2 equivalent in 2017.
• Third, the Court emphasized the continued increase in urbanization and soil sealing across the Brussels territory. Despite the RBC's repeated declarations of intent to halt soil sealing since 2012, the Court noted that urbanization and soil sealing continue to grow. The RBC's own documents acknowledge that impermeabilization rates doubled between 1955 and 2006, rising from 27% to 47% of the total surface area, with continued growth since then.
• Finally, the Court found that the RBC's regulatory tools remain obsolete. The current PRAS dates from 2001 and the Regional Urban Planning Regulation (RRU) from 2006 - regulatory instruments that have failed to curb soil sealing and are no longer adapted to climate change challenges as identified since their adoption.

The Judgment

Based on these findings, the Court ordered the RBC to take necessary measures to implement a moratorium on urbanization and impermeabilization of undeveloped sites and lands exceeding 0.5 hectares within its territory. The moratorium is subject to the following temporal limitations: (i) it must remain in effect until adoption of the revised PRAS, whose revision was initiated by government decree of 23 December 2021, and (ii) in any case, it must end no later than 31 December 2026. The Court determined that such a moratorium was both necessary and legally appropriate to: (a) mitigate the risk of aggravating damage from climate change effects in the RBC, and (b) allow for proper integration of these sites' future use into the PRAS revision process, which must include public consultation.

However, the Court rejected the plaintiffs' broader demands for specific prescriptive measures to be integrated into the RRU and the PRAS revision process. The Court found these requests too vague and imprecise to be enforceable, noting that a demand to integrate "literal and graphic prescriptions necessary to strengthen GHG absorptions" and "implementing an adaptation strategy" was insufficiently specific for verification of compliance.

In addition, the Court specifically declined to prescribe the exact measures the RBC must implement, recognizing that the Region possesses the necessary legal instruments to enforce the moratorium through various means, including instructing the delegated urban planning official to suspend permits, refusing permit applications, or adopting an ordinance establishing a moratorium. The Court emphasized that it would not interfere with the RBC's choice of specific implementation measures, while noting that any such measures involving private property rights would require legislative action due to constitutional protections of property rights.

Practical Implications and Implementation Uncertainties

The judgment has two key effects: first, it prohibits the issuance of new urban planning permits for undeveloped sites and lands exceeding 0.5 hectares, and second, it suspends the examination of pending permit applications for such sites and lands. Consequently, the large undeveloped sites of Wiels (Forest), Grand Forestier (Auderghem), and Carré des Chardons (Schaerbeek) are protected until the end of the moratorium. Simuilar protection applies to the Josaphat brownfield site (Schaerbeek) and the Bempt site (Forest), both of which have permit applications that have been submitted and are currently under review.

Nevertheless, the judgment creates significant implementation uncertainties, particularly regarding the scope of application to existing permits. A clearer distinction between: (i) permits already issued for sites where construction has not commenced, and (ii) permits for sites where construction has begun, would have provided greater guidance for implementation. This distinction is particularly relevant given the potential implications for property rights and legitimate expectations of permit holders.

One interpretation of the Court's reference to “undeveloped sites and lands” is that sites where construction has already commenced would fall outside the moratorium's scope. This interpretation would focus on the current physical state of the site rather than the permit status.

However, this interpretation remains subject to the RBC's implementation measures and potential clarification through administrative practice or subsequent judicial review. The judgment grants the RBC discretionary powers in choosing the specific measures to implement the moratorium, creating uncertainty about how the Region will interpret and apply the Court's order in practice.

From a regulatory perspective, extending the moratorium to already-granted permits would raise complex legal questions. According to established jurisprudence from the Belgian Constitutional Court and the European Court of Human Rights, a validly issued urban planning permit constitutes ‘property’ within the meaning of Article 1 of the First Additional Protocol to the European Convention on Human Rights.[1] Retroactive application of the moratorium to existing permits could potentially conflict with principles of non-retroactivity, legitimate expectations, and legal certainty.

Conversely, according to We Are Nature Brussels (one of the applicants), the judgment should be interpreted as requiring the RBC to prevent implementation of any permits that may have been issued for relevant sites. This interpretation argues that the judgment concerns suspension of urban development activity rather than merely prohibition of issuing new permits[2], suggesting a broader reading that would encompass all development activity regardless of permit status. 

Given these competing interpretations, real estate developers should: (i) conduct immediate portfolio reviews to identify all projects on undeveloped sites exceeding 0.5 hectares; (ii) assess the development status of such sites to determine potential exposure to the moratorium; (iii) consider alternative strategies such as focusing on sites below the 0.5-hectare threshold or brownfield redevelopment projects on already-built sites; and (iv) engage proactively with the RBC to seek clarification on the interpretation and implementation of the moratorium.

Our real estate and urban planning team remains available to assist developers in assessing the impact of this judgment on their portfolios and in developing strategies to mitigate associated legal and commercial risks during this period of regulatory uncertainty.