1. Introduction
When a contractual partner fails to perform, the creditor can resort to a range of remedies set out in Article 5.83 of the Civil Code, including (1) specific performance (“exécution en nature” / “uitvoering in natura”) and (2) damages (“réparation” / “herstel”).
Although these remedies are ordinarily performed by the debtor itself, they may also be implemented by the creditor through a mechanism known as replacement (“remplacement” / “vervanging”).
Replacement is well established in certain sectors – such as construction – but is less familiar in others, despite its practical usefulness (including, for example, in lease agreements).
2. Legal framework
Replacement is governed by Articles 5.85, 5.86, and 5.235 of the Civil Code.
3. Purpose
Replacement may serve either as a form of specific performance (Article 5.85) or as a form of compensation in kind (Article 5.86).
For example, where a contractor fails to build a wall and another contractor is consequently entrusted with the same work, this replacement constitutes specific performance: the third party performs the very obligation initially owed by the defaulting contractor.
On the other hand, where the wall has been built but defectively, and a third party is consequently entrusted with measures to remedy the defects, the replacement is a case of compensation in kind. The third party does not perform the original obligation, but repairs the harm caused by its defective performance.
This distinction can be significant where contracts contain replacement or limitation-of-liability clauses. Drafters must therefore carefully consider their wording to account for the dual nature of replacement (specific performance / compensation in kind) and to ensure either that both are covered or, conversely, that one of them is excluded.
4. Forms of replacement
Replacement may take one of three forms: judicial, pursuant to a contractual clause, or unilateral.
a. Judicial replacement
Pursuant to Article 5.235 of the Civil Code, where the nature of the obligation does not preclude it, the creditor may seek court authorisation to proceed with replacement. The main disadvantage of this mechanism is the potential length of the proceedings, although in practice, certain procedural tools may help mitigate delays in urgent situations.
b. Contractual replacement clause
Replacement may also be organised by a contractual clause. In practice, the difficulty in this case often stems from imprecise or poorly drafted clauses, which give rise to interpretative or validity disputes. For example, while a limitation-of-liability clause may cap replacement costs when replacement operates as compensation in kind, does it also apply where replacement is a form of specific performance? Well-drafted clauses in a thoughtful contract can address this issue.
c. Unilateral replacement
Under Article 5.85, paragraph 3, of the Civil Code, a creditor may, even in the absence of a judicial authorisation and a contractual clause, proceed unilaterally with replacement in cases of emergency or other exceptional circumstances, provided that it gives a written notification and keeps evidence of the debtor’s breach.
d. Valid replacement
If the replacement is validly carried out, the resulting costs must be borne by the debtor as replacement costs.
In contractual relationships, because replacement places the creditor in the position it would have been in had the debtor performed, the debtor remains entitled to payment of the contract price for this performance, even where that performance was carried out by a third party. If that price has not been paid yet by the creditor, it may be set off against the replacement costs incurred by the creditor.
e. Invalid unilateral replacement
For some time, the consequences of an invalid unilateral replacement were uncertain. In its judgments of 18 June 2020 (C.18.0357.N) and 28 September 2025 (C.24.0001.N), the Belgian Supreme Court clarified that where, without prior judicial authorisation, the creditor has the obligation performed by a third party without justification or negligently, it may not recover the replacements costs incurred but is nonetheless entitled to damages compensating the harm caused by the debtor’s non-performance or defective performance.
Accordingly, a creditor who has wrongfully proceeded with unilateral replacement is not necessarily deprived of all recovery. It may still obtain compensation for harm resulting from the debtor’s breach. Such damages may, however, be reduced by counter-damages owed to the debtor as a result of the invalid replacement. The debtor’s recoverable loss will cover the difference between its actual position and the position in which it would have been had the creditor not committed a tort or breach in carrying out the replacement.
5. Conclusion
For lawyers and contracting parties, replacement should not be overlooked: it is a practical and effective tool for breaking deadlocks and preserving the economic balance of the contract.
Our team can assist in assessing whether replacement is an appropriate remedy in your case, designing a strategy to implement a replacement – including in judicial proceedings –, drafting clear contractual clauses to avoid future disputes, or reviewing the enforceability of provisions allowing, limiting or excluding replacement.
Authors: Charles-Edouard Lambert and Catherine de Nonancourt (Simont Braun)
