To run a tunnel, the expropriating body may take only part of the subsoil (tréfonds) of a plot and leave the rest of the land to its owner. If the owner wants to build, the tunnel will require special foundations and anti-vibration devices: does that extra cost measure the depreciation of the remainder (dépréciation du surplus) before the expropriation judge (juge de l’expropriation)? In a reported decision of 6 December 2018, the Third Civil Chamber of the Cour de cassation (the French supreme court for civil matters) answered no, because it results from the siting of the public works and not from the taking (emprise, the part of the property taken); it did not, however, censure the valuation of the subsoil based on the ground, a choice that lay with the Court of Appeal.
The facts
The RATP (Régie autonome des transports parisiens, the Paris public transport operator) sought the compulsory purchase (expropriation) of part of the subsoil of a plot belonging to two owners, in order to place a tunnel there. The owners died during the proceedings and their heirs took over. The Paris Court of Appeal delivered two decisions, on 12 November 2009 and then, after an expert appraisal, on 29 June 2017: the latter set the dispossession indemnity (principal compensation, indemnité principale) and the reinvestment allowance (indemnité de remploi) due to the heirs.
On the depreciation of the remainder, the Court of Appeal found that the presence of the tunnel required additional works for the construction of a building with two basement levels: special foundations, anchored on either side of the tunnel at a level below it, and devices designed to neutralise the vibrations caused by passing trains. It held that the indemnity for depreciation of the remainder “is equal to the extra cost imposed by the presence of the tunnel” on such a construction (translated from the French, as are the quotations below), and stayed its decision on the amount until the heirs’ building project, first submitted to the RATP, was carried out.
The RATP appealed against both decisions, challenging the valuation of the subsoil as well as the way the depreciation of the remainder was measured.
The decision
The Cour de cassation partly quashed the decision of 29 June 2017 (Cass. 3e civ., 6 December 2018, appeal no. 17-24.312, reported). The appeal against the 2009 decision was declared lapsed on procedural grounds.
On the depreciation of the remainder, it relied on article L. 13-13, now L. 321-1, of the French Expropriation Code (Code de l’expropriation pour cause d’utilité publique) and recalled that “the indemnities awarded must cover the whole of the direct, material and certain loss caused by the expropriation”. By retaining the extra building cost due to the tunnel, the Court of Appeal breached that article “by compensating a loss which results from the siting of the public works and is not the direct consequence of the taking for which the expropriation was ordered”. The quashing covers only that finding and the stay that went with it; the case was sent back to the Paris Court of Appeal, differently composed.
On the value of the subsoil, by contrast, the Court rejected the RATP’s ground: the Court of Appeal, “which did not refer to the presence of the public works, but to the characteristics and situation of the land, the quality of the soil and the depth of the groundwater, chose, in its sovereign judgment, the method of valuing the subsoil it found most appropriate to the property in question”. The dispossession indemnity and the reinvestment allowance are therefore unaffected.
What this changes for valuation
Two losses, two causes. When the subsoil is taken to house public works, the owner loses a volume of their land, then has to live with the works installed in that volume. The expropriation judge compensates the first harm: the value of the subsoil taken, the reinvestment allowance, and the depreciation of the remainder that flows from the taking. The extra cost of foundations and anti-vibration devices stems from the siting of the tunnel and the passing trains; the Court held that it is not the direct consequence of the taking. The decision does not name the court with jurisdiction over that loss; in support of its ground on the subsoil, the RATP argued that damage resulting from the construction of public works falls to the administrative courts alone.
The depreciation of the remainder is not removed, it is measured differently. The decision does not exclude all depreciation of the remainder when subsoil is taken; it censures measuring it by the extra cost the works impose on a building. The valuer therefore looks for what the loss of the volume taken removes, in itself, from the value of the remaining land, by comparing its value before and after the taking, without including the constraints linked to the presence of the works. Depreciation of the remainder may be awarded whatever the nature of the property, as a 2019 decision on a partial compulsory purchase in a ZAC (zone d’aménagement concerté, a planned development zone) held; according to the 2025 decision on the refused easement, indemnities are set in euros and depreciation due to loss of access can be compensated in kind only with the owner’s consent.
The subsoil is valued from the ground. The Cour de cassation did not censure the valuation adopted, based on the land and the soil without reference to the works: the choice of method lay within the Court of Appeal’s sovereign judgment (appréciation souveraine), which it does not review. The report describes the land as it is, location, planning rules, nature of the soil, level of the water table, depth of the volume taken, and derives from it what that volume represents in the value of the plot, for example as a proportion of the surface land value, a customary method the decision does not examine; it explains the method adopted and does not refer to the works.
Classify each head of loss by its cause. Conversely, the same year, the landlocking of a garage the owners kept, resulting directly from the acquisition of the plots, was held to be a direct loss, compensable on top of the reinvestment allowance. The report lists each loss claimed, states whether it results from the taking or from the works, quantifies before the expropriation judge only the former and flags the others with their legal basis.
What the valuer takes from it
- The extra building cost imposed by public works sited in the expropriated subsoil results from the works, not from the taking; it does not measure the depreciation of the remainder before the expropriation judge.
- The depreciation of the remainder remains a separate head, quantified by the loss of value that the taking itself causes to the remaining land.
- The subsoil is valued from the land and the soil, as the Court of Appeal did, without reference to the works; the method, explained in the report, lies within the sovereign judgment of the trial judges (juges du fond: the expropriation judge and the Court of Appeal).
- The report classifies each loss by its cause, taking or works, and flags separately those that belong to another route.
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 dépréciation du surplus, juge de l’expropriation and indemnité principale complement this article. The two other 2018 decisions on compensable loss: Compulsory purchase: landlocked remaining garage is compensated and Compulsory purchase: occupier under precarious permit compensated. On the same theme: Compulsory purchase: a refused easement still leaves depreciation and Compulsory purchase in a ZAC: utilities, pollution and remainder. The decision is available on Légifrance.
What next
Is the subsoil of your land being compulsorily purchased for a tunnel or a network?
I value the volume taken from the land, the soil and the depth, then the depreciation of the remainder that results from the taking itself. The report sets apart the constraints due to the works, so that they are brought where they belong.
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).
