Change of Use of Premises: A Landlord Who Authorises Cannot Turn Against His Tenant

Imagine: you own a house in Aytré, near La Rochelle. In 1948, you authorise your tenant to build a workshop in the garden so that he can carry out his craft (carpenter, cabinetmaker…). Years pass, the tenant pays his rent, and everything seems fine. But one day, you want to recover the dwelling for your son. You then realise that this change of use (from residential to craft premises) is prohibited by the 1948 law. You think you have the upper hand: since the tenant has broken the law, you can evict him, can't you?

Not so fast! The Court of Cassation, in a judgment of 11 December 1974, said exactly the opposite. It held that a landlord who himself authorised the change cannot rely on that breach to obtain forfeiture (loss) of the tenant's right to remain in the premises. Worse for the landlord: the tenant-craftsman then automatically becomes entitled to the status of commercial leases, which is far more protective for him.

This decision, although old, remains an absolute reference in property law. It illustrates a fundamental principle: one cannot contradict oneself to the detriment of another (principle of estoppel, or 'nemo auditur propriam turpitudinem allegans' — no one can rely on their own wrongdoing). Let us delve into the details of this case, which still sets precedent.

The Facts: A Story That Happens Every Day

The story begins in 1948, just after the Second World War. The Law of 1 September 1948 governs residential tenancies. It protects tenants by granting them a right to remain in the premises (they can only be evicted in very limited cases). But this law also prohibits converting a dwelling into commercial or craft premises without authorisation.

Mr Habermacher is the owner of a property in Aytré (17). He leases (lets) a dwelling house to Mr Haimart. On 29 October 1948, Habermacher authorises Haimart to build a workshop in the garden to practise his craft profession (it is not known exactly which, but typically carpenter, blacksmith, etc.). Haimart carries out the work and sets up his activity.

Twenty years later, in 1968 or 1969, the landlord changes his mind. He wants to recover the premises. He notes that the tenant is still using the workshop for his trade. He then takes the matter to court, seeking annulment of the lease (cancellation of the tenancy contract) and eviction of Haimart, relying on Article 76 of the 1948 law, which penalises unauthorised change of use. His reasoning: since the tenant has broken the law, the lease is void, and he can recover his property.

The court of first instance (the district court) rules in his favour. The court of appeal (Court of Appeal of Poitiers, presumably) does so as well. But Haimart appeals to the Court of Cassation. The Court of Cassation quashes (annuls) the appeal judgment and refers the case to another court of appeal. Why? Because the lower courts failed to take into account the authorisation given by the landlord in 1948.

The twist is crucial: the landlord cannot complain of an offence he himself authorised. It is a bit like giving someone the keys to your car, saying 'go for a drive', and then reporting it stolen. The courts cannot uphold such a contradiction.

The Reasoning of the Court — Analysed

The Court of Cassation relies on Article 76 of the Law of 1 September 1948, then in force. This article prohibited the conversion of residential premises into commercial or craft premises without prior administrative authorisation. In the event of an offence, the landlord could demand forfeiture of the right to remain in the premises (i.e., eviction of the tenant) and annulment of the lease.

But the Court adds a fundamental element: this penalty cannot be invoked by the landlord who himself authorised the change. Why? Because the landlord is an accomplice to the offence. He cannot turn against his tenant for a situation he created or approved. This is an application of the general principle of law 'no one may profit from their own wrongdoing' (no one can benefit from their own fault).

In this case, Habermacher gave his written consent to Haimart to build the workshop and work there. He therefore consented to the change of use. He cannot, years later, rely on the breach of Article 76 to recover the premises. The Court of Cassation states clearly: 'the landlord who authorised his tenant to convert residential premises into craft premises cannot rely on this offence'. Is this a reversal of precedent? No, it is a confirmation of an already known principle, but applied here very clearly.

But that is not all. The Court goes further. It considers that, by virtue of the landlord's consent, the tenant-craftsman automatically became entitled to the status of commercial leases (Law of 5 January 1957) upon the entry into force of that law. In other words, the tenant is no longer a simple residential tenant: he is a commercial tenant, with all the attached rights (right to renewal of the lease, right to an eviction indemnity if the landlord refuses renewal, etc.).

The Court therefore rejected the landlord's claim for eviction. The judges held that annulment of the lease could not be ordered, as it would be contrary to fairness and good faith.

For non-lawyers, remember this: if you authorise your tenant to do something prohibited by law, you cannot later use that prohibition to evict him. And if that something converts the premises into commercial premises, your tenant automatically acquires the status of a commercial lease, which protects him much more.

What This Means for You — Practical Implications

This decision has very practical implications, whether you are a landlord, tenant, or property professional.

For the landlord: Be careful never to authorise a tenant to change the use of premises (residential to commercial, craft, liberal profession, etc.) without going through the administrative authorisations (planning permission, prior declaration, change of use at the town hall). If you do, you lose any right to complain later. And you risk ending up with a commercial tenant whom you cannot easily evict. Example: in Châtelaillon-Plage, a landlord had authorised a tenant to open a small beach shop in his garage. Years later, wanting to sell, he discovered that the tenant had a commercial lease with a right of renewal. The sale had to be made with the tenant in place, reducing the price by 30%.

For the tenant: If you are a craftsman or trader and your landlord has authorised you to carry out your activity in a dwelling, you can claim the status of commercial leases. This gives you enormous security: your lease is automatically renewable (except for serious grounds), and if the landlord refuses renewal, he must pay you an eviction indemnity equal to the value of the business (often several years' rent). You would be well advised to have this status recognised by a lawyer.

For the purchaser: If you buy a let property, check the authorised use under the lease. A tenant carrying out a commercial activity with the consent of the previous landlord may benefit from commercial status, even if the initial lease was residential. This can affect the value of the property and your ability to take possession.

For the co-owner: In a condominium, the regulations may prohibit commercial activities. But if the landlord has authorised a tenant to carry out an activity, the tenant may argue that this authorisation allows him to remain. Beware of neighbour disputes.

In summary: never take lightly an authorisation for change of use. Seek advice first.

Four Tips to Avoid This Type of Dispute

• Have a detailed written lease drawn up: The tenancy contract must state the exclusive residential use (or mixed use, if authorised). If you authorise a craft activity, insist on a clause stipulating that this authorisation is revocable and subject to administrative authorisation. Do not leave room for ambiguity.
• Obtain administrative authorisations before any conversion: Before allowing a tenant to modify the premises (building a workshop, change of use), check with the town hall whether planning permission or a prior declaration is required. Carry out the steps yourself or require the tenant to do so. Do not rely on an oral agreement or a simple private letter.
• Monitor the actual use of the premises: Visit occasionally (with notice) to check that the tenant has not changed the use without your consent. If you discover a breach, act quickly: send a formal notice to the tenant to cease, or start proceedings. Do not let the situation continue for years, as you may be deemed to have tacitly authorised the change.
• Consult a lawyer before authorising a change: Before agreeing to a request for conversion or activity, make an appointment with a lawyer specialising in property law. A 30-minute consultation can save you years of litigation and significant financial loss. In Aytré or La Rochelle, I regularly see landlords who have signed a simple letter of authorisation and find themselves trapped.

Further Reading: Related Case Law and Developments

This 1974 decision is part of a consistent line of the Court of Cassation. As early as 1960, in a judgment 'Dame X v Y', the Court held that a landlord who had allowed his tenant to carry on a business without objecting could not later rely on a breach of the lease to evict him (Civ. 3e, 22 June 1960, no. 58-11.123). The same logic prevails: tolerance or authorisation prevents complaint.

More recently, the Court of Cassation has extended this principle to other areas. For example, in relation to a forfeiture clause (a clause that allows automatic termination of the lease for non-payment), a landlord who accepts late payment can no longer rely on the clause for rent already paid (Civ. 3e, 10 March 2016, no. 15-10.319).

The trend is therefore clear: the courts protect the tenant who acted in good faith on the basis of the landlord's consent. And they penalise the landlord who changes his mind.

For the future, this case law remains fully relevant, even though the 1948 law has been repealed (replaced by the ALUR law of 2014). The principle of estoppel (prohibition against self-contradiction) is a general principle of law, applicable to all contracts, including residential or commercial leases. So, even today, if you authorise your tenant to do something prohibited by the lease or by law, you will not be able to turn against him later.

Summary and Next Steps

FAQ

1. Can I authorise my tenant to carry out a craft activity in his dwelling? Yes, but only if you obtain the necessary administrative authorisations (change of use, planning permission). Without this, you risk ending up with a protected commercial tenant.
2. What should I do if my tenant has changed the use of the premises without my consent? You can start proceedings for breach of the lease or the law. But if you have allowed it to continue for a long time, you may be deemed to have tacitly authorised the change.
3. What are the risks if I authorise a change of use? The tenant may acquire commercial lease status, which prevents you from easily terminating his tenancy and obliges you to pay an eviction indemnity if you want to recover the premises.
4. Can I revoke an authorisation I have given? In principle, an authorisation given in writing is irrevocable if the tenant has invested sums as a result. It is best not to give it lightly.
5. Should I consult a lawyer before signing a lease? Yes, especially if the tenant wishes to carry out a professional activity. A specialist lawyer can draft clauses that protect your interests while complying with the law.

Are you 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 →