A plot included in a development scheme carries a small building erected unlawfully, in a zone where building is prohibited, more than ten years ago. Its owner argues that the time bar protects it from demolition, so the acquiring authority must pay for it. In a reported decision of 15 February 2024, the Third Civil Chamber of the Cour de cassation (the French supreme court for civil and commercial matters) answers that, without a legally protected right at the date of the expropriation, such a building gives no right to any compensation, even if the action for demolition is time-barred. For the valuer, checking the permits comes before the figures.
The facts
By an order of 1 August 2017, the prefect of the Essonne declared the development of the Belles-Vues zone d’aménagement concerté (ZAC, a planned development zone), in the municipalities of Arpajon and Ollainville, to be in the public interest. By an order of 7 May 2019, the land required was declared immediately transferable to a société d’économie mixte (a semi-public company), including a plot belonging to a private individual on which a 20 m² building stood. The expropriation order was made on 9 September 2019. With no agreement on compensation, the acquiring company applied to the expropriation judge (juge de l’expropriation) of the Essonne.
Before the Paris Court of Appeal, the owner argued that, even if the building was unlawful, the time bar had run, since it had stood for more than ten years. In a judgment of 17 March 2022, the Court of Appeal stated that the loss relating to a building erected unlawfully gives no right to compensation, unless the criminal offence is time-barred. It saw this debate as a serious dispute (contestation sérieuse) within the meaning of article L. 311-8 of the Expropriation Code and fixed two alternative awards, with vacant possession. If the building is judicially recognised as unlawful: €4,572 as principal compensation (indemnité principale) and €914.40 as reinvestment allowance (indemnité de remploi), that is €5,486.40. If it is not: €74,360 and €8,436, that is €82,796. The acquiring company appealed.
The decision
The Cour de cassation quashed the judgment on that point, without remittal, that is without sending the case back to another court of appeal (Cass. 3e civ., 15 February 2024, appeal no. 22-16.460, reported decision), under articles L. 311-8 and L. 321-1 of the Expropriation Code.
The first of these texts requires the judge, where there is a serious dispute on the merits of the right, to fix as many alternative awards as there are possible scenarios. The second provides that compensation covers “the whole of the direct, material and certain loss caused by the expropriation” (translated from the French). The Court restated the rule it draws from it, citing decisions of 1975, 2010 and 2023: “only a loss based on a right that is legally protected at the date of the expropriation may be compensated”.
It concluded: “where its owner cannot invoke a right that is legally protected at the date of the expropriation, the dispossession of a building erected unlawfully and located on an unbuildable plot does not give rise to a right to compensation, even if any action for demolition is time-barred at the date of the expropriation”.
The Court of Appeal therefore could not fix alternative awards. It had found that the building erected on an unbuildable plot was unlawful, from which it followed that, “even if any action for demolition was time-barred, the expropriated owner could not invoke a legally protected right whose loss could give rise to a right to compensation”.
In the interest of the proper administration of justice, the Court ruled on the merits itself. It fixed compensation “by reference to the value of the bare land adopted in the judgment”, which the owner, who had not appealed, did not dispute: 381 m² at €12 per m², that is €4,572 as principal compensation, plus €914.40 as reinvestment allowance at the rate of 20%, a total of €5,486.40.
What this changes for valuation
The right before the value. Before valuing a building, an extension or an improvement, the report establishes what right it rests on at the date of the expropriation: planning permission, prior declaration, planning rules for the plot. On an unbuildable plot, neither the age of the building nor the time bar on demolition is enough to create a right, so the time bar alone no longer justifies two scenarios. If lawfulness itself is disputed on the facts, for example over the existence of a permit, the report may quantify the land and the building separately, so that the judge has both amounts.
A considerable gap. The Court of Appeal’s two scenarios ranged from €5,486.40 to €82,796, a gap of €77,309.60, depending on whether the building’s unlawfulness was judicially recognised or not. With the building excluded, the principal compensation comes down to the value of the bare land, here €12 per m² for an unbuildable plot, and the reinvestment allowance, which depends on it, falls from €8,436 to €914.40. Everything then turns on the land: area, planning rules, sales of comparable land subject to the same constraints.
Two decisions that fit together. On 9 November 2023, in a purchase notice case (délaissement, where the owner forces a public body to buy), the Cour de cassation approved a discount on the value of a property where a significant part of the buildings had been erected without planning permission, even if the action for demolition was time-barred. The more recent 2024 decision does not contradict that solution: it concerns an unlawful building on an unbuildable plot, which is not compensated at all. In both cases, the time bar does not make the building lawful, and the unlawfulness found did not call for alternative awards. The 2024 decision does not settle the case of buildable land; the report then describes the position of each building.
What remains compensable. The test is the legally protected right, not the physical presence of the building. In 2018, without ruling on that concept, the Court accepted that an occupier holding a free and precarious authorisation still in force at the time of the expropriation was entitled to compensation. Other heads of loss follow their own rules, such as the trading loss of a partly evicted business operator. The case of the owner who has neither responded to the offers nor served a written submission raises a separate, procedural question. The Charte de l’expertise en évaluation immobilière (the French property valuation charter) devotes a paragraph to compulsory purchase compensation (6th edition, November 2025, Title III, § 1.20).
What the valuer takes from it
- Only a loss resting on a legally protected right at the date of the expropriation is compensated; the report checks that right before valuing.
- An unlawful building on an unbuildable plot gives no right to any compensation, time bar or not.
- Compensation then comes down to the bare land, and the reinvestment allowance is calculated on that amount alone.
- The report classifies each building according to its permits and the planning rules for the plot, documents requested at the start of the assignment; the decision does not settle the case of buildable land.
Further reading
The Compulsory purchase and pre-emption page describes the assignment, its timescale and its fee. The guide Compulsory purchase of my business premises: what compensation? and the glossary entries indemnité principale, indemnité de remploi and juge de l’expropriation complement this article. On other points of compulsory purchase compensation: Partial eviction of a business: separate trading loss compensated and Silent owner in compulsory purchase: award may exceed the offer. On the same theme: Unauthorised buildings: discount despite time-barred demolition and Expropriated red-zone land: a draft risk plan does not count. The decision is available on Légifrance.
What next
An unauthorised building on the land being compulsorily purchased from you?
I first check the permits and planning rules for each building at the date of the compulsory purchase, then quantify what the law allows to be compensated, land and reinvestment allowance included. The written submission separates what rests on a right from what cannot be compensated.
Free quote, by email or by phone. No commitment before the quote is accepted. Fees are never linked to the value of the property (Charte de l’expertise, Title I, §2.1).
