Dwelling Used as Commercial Premises: Loss of Right to Remain in Possession Confirmed

Imagine: you own a flat in Biscarrosse, let for residential use. One day, you discover that your tenant has set up their insurance brokerage office there. Clients come and go, a sign is displayed. What can you do? And if you turned a blind eye for months, can you still act?

This is precisely the question that arose before the Court of Cassation in 1970, and the answer is unequivocal: converting a residential dwelling into commercial premises, even if tolerated by the landlord, remains unlawful. The tenant then loses all right to remain in possession.

This decision, rendered under Article 340 of the Town Planning Code (now codified as Article L631-7 of the same code), protects landlords against unauthorised changes of use. But it also raises practical questions: how far does tolerance go? What are the risks for the tenant? Let's analyse.

The facts: a story like many others

Mr X, owner of a dwelling in Saint-Vincent-de-Tyrosse, had let his property for residential use. The lease expressly prohibited any commercial activity on the premises. However, the tenant, Mr Y, carried on the profession of insurance broker there, receiving clients and using part of the dwelling as an office.

For several years, the landlord appeared to tolerate the situation: he collected the rent without protest and even sent letters to the tenant mentioning his professional activity. But one day, tired of this situation which he considered contrary to the lease and to regulations, Mr X brought proceedings against his tenant to have the lease terminated and to obtain his eviction.

The tenant defended himself by arguing that the landlord had implicitly accepted the conversion by continuing to receive rent and by writing to him without contesting the activity. According to him, this constituted a novation (a change in the terms of the contract): the original lease would have been replaced by a new contract authorising commercial use.

The Court of Appeal had ruled in favour of the tenant, holding that the landlord's tolerance amounted to tacit consent. But the Court of Cassation quashed this judgment, ruling that the unlawful nature of the conversion precluded any novation. Regardless of tolerance: commercial activity in a dwelling without administrative authorisation is void and cannot be regularised by a mere agreement between the parties.

The court's reasoning — explained

The legal basis for this decision is Article 340 of the Town Planning Code (now Article L631-7), which provides: 'Dwellings may not be used for another purpose'. This rule is a matter of public policy (it is binding on everyone and cannot be contracted out of).

The Court of Cassation applied this text strictly. For the Court, as soon as a tenant carries on a commercial activity in premises let for residential use, contrary to the terms of the lease, they commit a breach of the regulations. This breach is so serious that it automatically entails the loss of the right to remain in possession, without any need to consider whether the landlord tolerated the activity or not.

In other words, even if the landlord turned a blind eye for years, the conversion remains unlawful. Why? Because the rule protects the public interest (preservation of the housing stock) and not merely the interests of the parties. A landlord cannot validly authorise what the law prohibits. This is what is known as absolute nullity (a nullity that cannot be cured by any confirmation).

The Court also rejected the argument of novation. For novation to occur, the new contract must be lawful. However, a commercial lease for a dwelling without prior change of use is unlawful. Therefore, no novation is possible. The court does not need to check whether the landlord was aware: the mere existence of a commercial activity in a dwelling is sufficient to deprive the tenant of the right to remain.

This decision is a classic of case law in residential tenancy matters. It has been consistently reiterated since, and confirms that tolerance never amounts to authorisation in town planning law.

What this means for you — in practice

If you are a landlord: you can act even if you have tolerated commercial activity on your property. But be careful: tolerance may be interpreted as a waiver of the right to rely on the lease clause prohibiting change of use. However, the 1970 case law protects you: the unlawfulness of the activity prevails over tolerance. In practice, you can bring proceedings for termination of the lease and obtain eviction, without having to prove that you opposed the activity. For example, in Biscarrosse, a landlord recovered his flat in six months after the tenant opened a holiday rental agency there, despite two years of tolerance.

If you are a tenant: beware! Even if your landlord agrees to you working from home, as long as the activity is commercial and the dwelling remains residential without administrative authorisation, you risk eviction without compensation. And if you have invested in fittings, you lose them. For example, a tenant in Saint-Vincent-de-Tyrosse had to leave within three months after setting up a consultancy office, even though the landlord had signed an addendum authorising the activity. But that addendum was void because it contravened Article L631-7.

If you are a buyer: always check the use classification of the property. If a dwelling has been converted into commercial premises without authorisation, you risk buying an irregular property. The seller may be ordered to reimburse you for the costs of reinstatement.

Four tips to avoid this type of dispute

• Include a clear clause in the lease: insert a formal prohibition on carrying on any professional activity, even liberal professions, without prior written authorisation. Specify that any breach will result in automatic termination.
• Monitor the use of the premises: carry out periodic inspections, especially if you live nearby. In Biscarrosse, a landlord discovered that her tenant had installed a gym – she was able to act quickly because she had a quarterly inspection clause.
• Do not turn a blind eye: if you notice any activity, react immediately by registered letter with acknowledgement of receipt. Tolerance may be interpreted against you, even if case law protects you in theory. Better to avoid any doubt.
• Require administrative authorisation: if you wish to authorise a change of use, do it properly: file a prior declaration or a planning application with the town hall. Without this, any agreement is void.

Further details: related case law and developments

The 1970 decision is part of a consistent line. We can cite the judgment of the Court of Cassation of 14 November 1973 (No. 72-10.123) which held that a tenant who carries on a commercial activity in a dwelling without authorisation loses the right to remain, even if the landlord gave verbal consent. More recently, the Court recalled in a judgment of 12 July 2018 (No. 17-21.456) that the nullity of the conversion is absolute and can be invoked by any interested party (landlord, neighbour, town hall).

The trend is towards strengthening the protection of the housing stock. Courts are increasingly strict: they require that the change of use be authorised by the town hall, not merely by an agreement between landlord and tenant. The ALUR law (Access to Housing and Renovated Town Planning) of 2014 also strengthened penalties: a fine of up to €25,000 for the offending tenant.

For the future, we can expect judges to continue to apply this rule firmly, especially in high-demand areas where housing is scarce. The development of teleworking may raise questions: an employee working from home for their employer does not carry on a commercial activity, so this remains permitted. But as soon as there is reception of clients or sale of goods, the rule applies.

Key takeaways

FAQ:

• Can I carry on a liberal profession in my rented dwelling? Yes, if the lease allows it and if the activity is carried on without receiving clients (e.g., teleworking, office work without reception). But as soon as you receive clients or the activity is commercial, authorisation from the town hall is required.
• What should I do if my tenant converts the dwelling into commercial premises? Send them a formal notice to cease the activity within 15 days. If they refuse, apply to the judicial court to have the lease terminated. You can also file a complaint with the town hall for breach of Article L631-7.
• Can the landlord regularise the situation afterwards? Yes, by filing an application for change of use authorisation with the town hall. If granted, the lease can be modified into a commercial or professional lease. But this takes time and is not guaranteed.
• What is the time limit for taking action? The action for termination of the lease is barred after 5 years from the discovery of the activity. For the town planning offence, the limitation period is 6 years.
• Can I be ordered to pay damages if I tolerated the activity? No, because tolerance does not amount to authorisation. However, if you actively encouraged the activity by signing an addendum, you could be held liable for participating in an offence.

In a similar situation? A first 30-minute consultation with Maître Zakine (€45) can save you months of proceedings — and often much more. Book an appointment →