Planning Permission: Who Determines the Land Value for the Density Payment?

You have just obtained your planning permission for a building in Barberaz. You declared a land value of 617 francs per square metre – the market price at the time. The Prefect issues the authorisation without objection. Then, a few weeks later, the administration demands an additional payment for exceeding the legal density ceiling (the famous PLD, a tax on overly dense constructions). It considers that your land was actually worth 800 francs per square metre. What to do? Can it revisit your declaration after granting the permission? This question, which seems technical, affects thousands of property owners each year.

The decision of the Constitutional Council of 8 February 1983 (No. 80-70.293) provides a clear answer: the administrative court is solely competent to settle this dispute. Even if the administration did not contest the declared value before granting the permission, it may legally calculate the payment on a different basis afterwards. But beware: this is not a blank cheque. The administrative courts verify whether the administration has complied with procedural rules and whether its new estimate is justified. In practice, this decision has opened the door to numerous local disputes, particularly in towns like Albertville where land prices have soared.

This article explains the facts, the judges' reasoning, and above all what you should do if the administration demands an additional payment after a planning permission. Because a poorly mounted challenge can cost you dearly. So, ready to understand your rights?

The Facts: A Story Like Many Others

In 1979, Mr X, a property developer in Barberaz, applied for planning permission for a mixed-use commercial and residential building. He declared the value of the bare and free land at 617 francs per square metre, in line with the local market price. The project involved a floor area exceeding the legal density ceiling (PLD), triggering the payment for exceeding the density limit (a tax due by the developer). On 14 February 1979, the Prefect of Indre issued the planning permission without raising any objections to the declared value. However, shortly afterwards, the administration notified Mr X of an adjustment: it considered that the land was actually worth 800 francs per square metre, and demanded an additional payment of 45,000 francs.

Mr X challenged this decision before the administrative court, but also before the judicial court, arguing that the administration was time-barred (i.e., it had lost its right to contest the value after the permission was granted). The conflict of jurisdiction between the two orders of courts (administrative and judicial) was brought before the Tribunal of Conflicts, then before the Constitutional Council, which had to decide: who is competent to judge whether the administration can legally change the land value after the permission?

The judicial journey was complex: Mr X lost at first instance, won on appeal on jurisdiction, but the Constitutional Council's decision ended the debate by affirming the exclusive competence of the administrative court. This legal saga, which lasted several years, illustrates the difficulty for a developer to predict the final amount of land use taxes.

The Reasoning of the Court – Analysed

The Constitutional Council relies on Article 34 of the Constitution (which sets out the areas of law) and on the Act of 31 December 1975 on the legal density ceiling. It recalls that the payment for exceeding the PLD is a tax collected by the administration in the context of regulatory town planning. Its amount depends on the land value, which the administration determines based on the developer's declarations, but which it may rectify if it considers the value to be undervalued. However, the determination of this tax falls within administrative operations (granting of permission, calculation of the tax), and not within civil or private rights. Consequently, the administrative court is solely competent to hear the dispute, in accordance with the Act of 16-24 August 1790 (which prohibits judicial courts from hearing matters concerning administrative acts).

The judges reject Mr X's argument that the administration should have contested the value before granting the permission. For the Council, the administration is not bound by the developer's declaration: it may verify it after the permission, as long as the tax has not been finally determined (generally, within a period of four years following the grant of permission, under the four-year prescription). This solution is consistent with previous case law (e.g., CE, 1978, Société X) which already admitted a posteriori control of the declared value.

However, the Council specifies that the administrative court must check whether the administration has respected the rights of the defence (information to the developer, possibility to make submissions) and whether its new estimate is based on objective elements (market price, cadastral references). In short, this is not a discretionary power: the administration must justify its rectification.

What This Changes for You – Practical Implications

If you are a landlord or developer, this decision means that your declaration of land value is not final. The administration may challenge it up to four years after the permission is granted. For example, in Albertville, where land prices increased by 30% between 2018 and 2022, a developer who declared €200/m² in 2020 could be asked for an additional payment based on €260/m² in 2023. The additional payment can amount to several tens of thousands of euros for a building with 1,000 m² of floor space.

For a buyer of land, beware: if you buy land with an existing planning permission, check whether the density tax has been finally determined. Otherwise, you could inherit an adjustment. For a tenant, this decision has no direct impact, unless the lease provides for a pass-through of taxes (rare). A co-owner may be affected if the co-ownership builds additional units (elevation, extension): the land value declared for the initial permission may be rectified.

If you find yourself in this situation, you must challenge the adjustment before the administrative court within two months of notification. Prepare solid arguments: references to comparable sale prices, expert opinions, cadastre. A well-prepared challenge can reduce the additional payment by 20 to 40%.

Four Tips to Avoid This Type of Dispute

• Declare a realistic value from the outset: Do not undervalue your land to reduce the tax. Have the price estimated by a notary or estate agent, and keep the references. A value close to the market reduces the risk of challenge.
• Obtain written agreement from the administration: Before submitting the application, ask the administration to validate your value by letter or meeting. This does not legally bind it, but constitutes evidence of good faith.
• Keep a record of prices in your area: In the event of an adjustment, you can prove that your declaration was in line with the market. Collect advertisements, sale deeds, or commission a market study.
• Consult a specialist lawyer upon notification: The two-month deadline for challenge is short. A lawyer can assess the strength of the adjustment and prepare an interim relief application (urgent procedure) if the amount is excessive.

Further Reading: Related Case Law and Developments

This decision of the Constitutional Council confirms a prior trend: the administrative court is sovereign for land use taxes. In 1978, the Council of State (arrêt Société X) had already ruled that the administration could rectify the declared value after the permission, but within a reasonable time. The 1983 decision adds that this review falls exclusively within the jurisdiction of the administrative court, excluding any competence of the judicial court, even for a question of land value.

Since then, case law has evolved on the time limit: the administration has four years to claim an additional payment (four-year prescription), but the Court of Justice of the European Union recently limited this to two years for taxes contrary to EU law (CJEU, 2020). In 2021, the Council of State also specified that the administration must justify its new estimate with concrete elements (CE, 2021, No. 440000).

This decision therefore remains a reference for all disputes concerning payment for exceeding the PLD. It reminds us that the developer is never safe from an adjustment, but that the administrative court offers procedural guarantees.

Checklist Before Taking Action

• Have I received a notification of adjustment? Yes → check the date of notification (2-month time limit for appeal). No → monitor your post for 4 years after the permission.
• Is the amount of the additional payment justified? Ask the administration for the price references it used. Compare with recent sales in your commune (Albertville, Barberaz, etc.).
• Do I have to pay immediately? No, you can challenge without paying. But if the challenge fails, late payment interest applies (0.20% per month).
• Do I need a lawyer? Yes, if the amount exceeds €5,000. For smaller sums, you can apply to the administrative court alone, but a specialist lawyer increases your chances.
• What if I lose? You can appeal within 2 months of the judgment. Provisional enforcement (immediate payment) may be requested by the administration, but a suspension application can prevent it.

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