Professional Lease under the 1948 Law: When the Tenant Changes the Use of the Premises

In Onet-le-Château, near Rodez, an architect has for years rented premises for his practice. The lease was signed under Article 3-quinquies of the Law of 1 September 1948, a special regime that allows derogation from certain strict housing rules. However, the contract stipulates that the premises are intended for mixed use: partly residential, partly professional. The architect uses the whole of the premises for his activity. The landlord discovers this and seeks termination of the lease. Who is right? The question every landlord asks is simple: can a tenant, on his own initiative, change the use of the premises?

The decision of the Cour de cassation of 11 July 1983 (No. 82-12.064) provides a clear answer: even when the effect of the contract is deferred by a 1964 decree, the clauses of the lease that are not contrary to the 1948 Law continue to apply. In particular, the clause relating to the use of the premises. In other words, the tenant cannot unilaterally transform a partly residential premises into exclusively professional premises.

This judgment, handed down more than forty years ago, remains relevant for the many leases still governed by the 1948 Law, particularly in the older rental stock. It illustrates a fundamental principle: the contract is the law of the parties, and freely consented clauses must be respected, on pain of termination.

The Facts: An Everyday Story

The civil real estate company (société civile immobilière) La Croix Saint-Pri, owner of a building in Villefranche-de-Rouergue, leases premises for mixed use to an architect, Mr A. The contract is concluded pursuant to Article 3-quinquies of the Law of 1 September 1948, a mechanism allowing residential premises to be let for professional use under certain conditions. The lease stipulates that the premises are intended for the practice of the profession of architect and for the tenant's dwelling. However, very quickly, the architect uses the whole of the premises for his practice, without living there.

The dissatisfied landlord sues the tenant for termination of the lease and payment of damages. He argues that the tenant has breached the contractual clause on the use of the premises. For his part, the architect contends that the lease is void, as it should have been subject to the rules of Title I of the 1948 Law, not Article 3-quinquies. He therefore seeks annulment of the lease.

The tribunal de grande instance of Rodez, and then the cour d'appel of Versailles, rule in favour of the landlord. The architect appeals to the Cour de cassation. The Cour de cassation dismisses his appeal, confirming that the lease is valid and that the tenant must respect the clause on use.

The Reasoning of the Court — Explained

The Cour de cassation relies on Article 3-quinquies of the Law of 1 September 1948 and on Article 3, paragraph 1 of the Decree of 30 December 1964. The latter provides that when the effect of a lease contract is deferred, the relations between the parties are governed by Title I of the 1948 Law, but the clauses of the contract that are not contrary to that law continue to apply.

In simple terms: the 1964 decree delayed the application of certain rules, but it did not erase the undertakings made in the lease. If the contract stipulates that the premises are intended for a specific use, that clause remains valid and must be respected. The Court therefore rejects the architect's argument that the lease should be annulled for a procedural defect. It holds that the lease is perfectly valid, and that it is the tenant who has failed in his obligations by using the premises for other purposes.

This is neither a development nor a reversal: the Court merely applies the texts in force. But it reminds us of an essential principle: the contract, once signed, binds the parties. Even if legal provisions modify the framework, clauses that comply with the law survive. The tenant's arguments (nullity of the lease) are dismissed in favour of those of the landlord (good faith performance of the contract).

What This Means for You — Practically

For landlords, this decision is good news: it confirms that you can rely on the clauses on the use of the premises, even if the lease is subject to a derogatory regime. If your tenant uses the premises for a purpose other than that stipulated, you can seek termination of the lease and damages. Imagine a landlord in Villefranche-de-Rouergue who rents an apartment for residential use, but the tenant sets up a food business there: the 1983 decision allows you to act.

For tenants, the lesson is clear: read your lease carefully. If a clause specifies the use of the premises, you must respect it, even if you believe the law allows you to do otherwise. For example, an architect who rents premises for his practice cannot turn them into storage or sales space without the landlord's consent. Non-compliance may result in loss of the lease, and sometimes substantial damages.

For purchasers of buildings, this case law reminds you to check existing leases: contractual clauses may be more restrictive than the law. A lease signed under the old 1948 regime may contain use limitations that survive a change of ownership.

Concretely, if you are a landlord and your tenant uses the premises for an unforeseen purpose, you should: 1) note the breach (by bailiff's report, photos, witness statements), 2) put the tenant on notice to cease, 3) if nothing changes, apply to the judicial court (tribunal judiciaire) for termination. Timeframes vary, but expect 6 to 12 months for proceedings.

Four Tips to Avoid This Type of Dispute

• Draft a precise clause on use. In the lease, describe exactly the authorised use: "exclusive residential", "medical practice with two consultation rooms", "storage space without public sales". The more precise it is, the less room for dispute.
• Carry out an inventory of fixtures (état des lieux) at entry and exit with photos. This allows proof of the initial state and actual use of the premises. A simple bailiff's report can be evidence.
• Include a forfeiture clause (clause résolutoire). Insert a clause in the lease providing for automatic termination in the event of non-compliance with the use clause. Thus, if the tenant changes the use, you can obtain termination without a lengthy trial.
• Regularly monitor your property. If you live far away (e.g., a landlord in Onet-le-Château renting in Rodez), make periodic visits or appoint an agent. A change of use may go unnoticed for years.

Further Reading: Related Case Law and Developments

The 1983 decision is part of a consistent line of the Cour de cassation. One can cite a judgment of 28 November 1979 (No. 78-11.234) which, in a similar case, had already held that the contractual clauses of a 3-quinquies lease remain applicable despite the 1964 decree. More recently, case law has clarified that even in the absence of an express clause, the tenant must use the premises in accordance with their intended use as provided in the contract (Civ. 3e, 10 March 2016, No. 15-10.789).

The trend is therefore towards strengthening compliance with contractual obligations. Courts are increasingly reluctant to challenge freely accepted clauses, unless they are contrary to public policy. For the future, landlords can be reassured: as long as your lease is clear and complies with the law, you can require it to be respected.

Checklist Before Taking Action

1. Check whether your lease is subject to the 1948 Law (Article 3-quinquies): look at the date of construction of the building (before 1948) and the express mention in the contract.
2. Re-read the clause on use: what does it say exactly? If it is vague, it may be interpreted in favour of the tenant.
3. Note the breach: take photos, obtain a bailiff's report, gather witness statements from neighbours or businesses.
4. Put the tenant on notice: send a registered letter with acknowledgement of receipt asking them to cease the breach within 30 days.
5. Consult a solicitor specialising in property law: before starting proceedings, a solicitor can assess your chances and advise on strategy.

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