In Belgium

An obligation of means (obligation de moyens / middelenverbintenis) is a legal obligation whereby a party undertakes to deploy all reasonable efforts to achieve a goal, without guaranteeing the outcome. The distinction between obligations of means and obligations of result is fundamental in Belgian civil law.

In rental law, obligations of means apply to:

  • A property manager’s duty to find a suitable tenant
  • An architect’s advisory role during renovations
  • A landlord’s duty to take reasonable steps to resolve neighbourhood disturbances affecting the tenant
  • A real estate agent’s obligation to market the property effectively

How it works

Burden of proof. The key difference lies in who must prove what. With an obligation of means, the creditor (the person to whom the obligation is owed) must prove that the debtor failed to act with reasonable care and diligence. This is more demanding than for an obligation of result.

Standard of care. The debtor is measured against what a normally prudent and diligent professional would have done in the same circumstances. This is assessed objectively, not based on the individual’s personal capabilities.

Contractual context. Many professional service contracts in the rental sector create obligations of means. A property management contract, for instance, typically obliges the manager to use best efforts to collect rent, maintain the property and handle tenant relations — but does not guarantee zero vacancies or no arrears.

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Good to know
When hiring a property manager or agent, check whether the contract describes their obligations as “means” or “result”. An obligation of means makes it harder for you to claim compensation if things go wrong, because you must prove negligence rather than simply pointing to a failed outcome.

Practical example

A landlord hires a property manager to find a tenant for a studio apartment. The manager advertises on major platforms, conducts viewings and screens candidates. After 3 months, no suitable tenant is found. The landlord claims the manager failed. The court rules this is an obligation of means: the manager demonstrated reasonable diligence (advertising, viewings, screening). The market conditions, not negligence, explain the vacancy. No liability is found.