Industrial Nuisances: When the Expert Sets the Works and the Judge Controls

Imagine: you have just bought a house in Saint-Julien-en-Genevois, with a garden where you hoped to enjoy a quiet coffee. But for a few weeks, a fine white dust covers your terrace, and an acrid smell stings your eyes every time the wind turns. The neighbouring cement works is running at full capacity, and you wonder: how much of this nuisance must I put up with? Can I require works to be done, and who will decide their exact nature?

This question is asked every year by hundreds of owners and tenants faced with industrial, craft or even agricultural activity that exceeds the normal inconveniences of neighbourhood. The courts are regularly seised to decide this conflict between the right to operate and the right to tranquillity.

The ruling handed down by the French Supreme Court on 5 December 1973 (no. 72-11.931) provides a clear answer: judges may entrust to an expert the task of supervising the execution of the prescribed works, but they do not abandon their decision-making power to him. In other words, the expert is a technician, not a second judge. This decision, still relevant today, protects victims of abnormal disturbances by guaranteeing that the final word belongs to the court.

The Facts: A Story Like Many Others

In the early 1970s, a cement works located in a peri-urban area – one could imagine the region of Bonneville – emitted fumes and dust that greatly inconvenienced its neighbours. Mr X, owner of an adjacent house, and several other residents noticed that their façades were blackening, their gardens were covered with a whitish deposit, and the air sometimes became unbreathable.

After complaints went unanswered, they sued the company. Their claim? Cessation of the disturbance and compensation for their loss. The trial judges, after hearing the parties, ordered an expert assessment to evaluate the reality and extent of the nuisances. The appointed expert submitted his report: he confirmed that the emissions exceeded the normal inconveniences of neighbourhood. Armed with this conclusion, the neighbours hoped to succeed without a new trial.

But the cement company contested. It argued that the judgment, by prescribing works "in accordance with the directives and under the supervision of the expert", had unlawfully delegated judicial power to a technician. According to it, only the judge could decide on the measures to be taken; the expert had only an advisory role. The Court of Appeal had nevertheless validated this formula, and the French Supreme Court was seised to decide this point of law.

The Reasoning of the Court — Analysed

The French Supreme Court dismissed the cement company's appeal. It affirmed that the trial judges had not abandoned their power of control by entrusting the expert with the task of monitoring the execution of the works. Why? Because the operative part of the judgment itself fixed the nature of the works to be carried out – reducing dust and fume emissions – and the expert was merely charged with supervising their technical implementation.

The main legal basis is Article 1240 of the Civil Code (formerly Article 1382), which provides that "any act of a person which causes damage to another obliges the person through whose fault it occurred to make reparation". In matters of neighbourhood disturbances, case law applies this text extensively: as soon as the disturbance exceeds the normal inconveniences of neighbourhood – that is, what can reasonably be expected in a residential area – the responsible party must cease the disturbance and compensate the victim, without any need to prove intentional fault.

This decision confirms a constant trend: judges may use experts to enlighten them on technical questions (measurement of nuisances, feasibility of works), but they retain control of the dispute. The formula "in accordance with the directives and under the supervision of the expert" is not a delegation of power, but a practical modality of execution.

In this case, the expert had been given a purely technical mission: to ensure that the prescribed works complied with the requirements of the judgment. The judge retained the possibility of deciding any disagreement on the execution, and the parties could always return to him in case of difficulty. The solution is therefore balanced: it allows rapid implementation of measures while preserving judicial control.

What This Means for You — Practically

If you suffer from an abnormal neighbourhood disturbance – noise, smell, dust, vibrations – this case law gives you a powerful lever. The judge may, in his judgment, order specific works AND appoint an expert to monitor their completion. Concretely, you do not have to constantly battle to ensure the works are done correctly: the expert keeps an eye on things.

Let's take a numerical example: in Bonneville, an owner suffering from odour nuisances from a waste treatment plant obtains in court the installation of an air filtration system. The court orders the works and appoints an expert to verify that the filter is installed within six months and complies with applicable standards. If the industrialist delays, the expert reports it to the judge, who may impose a penalty payment (astreinte).

For landlord owners, if your tenant complains of nuisances caused by an industrial neighbour, you can support them in their approach: the disturbance affects the enjoyment of the property and may justify a rent reduction if you do not react. But it is up to the tenant or the occupying owner to act directly against the author of the disturbance.

For purchasers, before buying a property near a potentially polluting activity, check whether court decisions have already been made. A judgment ordering works under expert supervision is a sign that the disturbance is recognised and that solutions exist. You can also insert a clause in the preliminary sale agreement to protect yourself.

Four Tips to Avoid This Type of Dispute

• Before buying or renting, investigate the industrial neighbourhood. Consult the local urban plan (PLU) to identify activity zones, and inquire at the town hall about complaints already filed. In Saint-Julien-en-Genevois, for example, some residential areas adjoin craft zones: it is better to anticipate.
• Keep evidence of the nuisances. Photos, videos, written testimonies, registered letters to the author of the disturbance. The stronger your file, the more inclined the judge will be to order effective measures.
• Do not wait until the disturbance worsens. Once the disturbance exceeds the normal, act: registered letter, then conciliation, then summons. Judges appreciate responsiveness.
• Consult a specialised lawyer before accepting mediation or a private expert assessment. A poorly negotiated agreement may deprive you of subsequent remedies. The court-appointed expert is neutral; a private expert chosen by the industrialist is not.

Further Reading: Related Case Law and Developments

This 1973 decision is part of a consistent line. Already, a French Supreme Court ruling of 19 November 1964 (no. 63-10.499) had admitted that the judge could prescribe works and entrust their control to an expert. More recently, in a ruling of 10 September 2015 (no. 14-18.053), the Court recalled that the judge cannot delegate his judicial power, but may entrust a technical mission to an expert, including for fixing the modalities of execution of works.

The trend is therefore pragmatic: courts seek to resolve neighbourhood disputes in a concrete manner, without multiplying hearings. The expert is a judicial auxiliary, not a decision-maker. This solution avoids the parties having to return constantly to the judge for technical details, while guaranteeing that the final decision – notably the cessation of the disturbance – remains in the hands of the magistrate.

For the future, one can expect judges to use this technique more and more, especially in environmental litigation where corrective measures are complex and evolving (dust removal installations, sound insulation, etc.).

Summary and Next Steps

What to remember:

• An abnormal neighbourhood disturbance entitles you to compensation and cessation of the nuisances.
• The judge may order works and appoint an expert to supervise their execution, without losing his power of control.
• The expert is a technician: it is the judge who decides in the last resort.

What to do if you are a victim:

1. Gather evidence (photos, videos, attestations, cleaning bills).
2. Send a registered letter with acknowledgement of receipt to the author of the disturbance asking him to cease.
3. If nothing changes, seise the tribunal judiciaire (or the tribunal de proximité depending on the amount of the loss).
4. Ask the judge to order an expert assessment and works under expert supervision.

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 →