Development tax: how much in 2025?

The development tax is a local tax levied by the municipality and the department and, only in Île-de-France, by the region. It is mainly used to finance the public facilities (networks, roads) needed for future construction and development.

It is not an annual tax, it is due only when certain construction works are carried out.

Which operations are involved?

The development tax applies to all development, building, reconstruction and expansion operations of buildings or installations, which require a city planning authorization (building or development permit, prior declaration).

It applies as soon as a surface bounded by walls and covered shall be created, provided that the area exceeds 5 mths² and the height of the ceiling is greater than or equal to 1.80 m.

What rate is applied for this tax?

The value of the project is calculated either per unit (tent site, parking space, wind turbine...) or per m² of surface area (swimming pool, photovoltaic panel...). The percentages (rates) for the municipalities, departments and regions are applied to this value.

The development tax is the sum of these results.

• The annual rate of municipal share may vary from 1 % to 5 %. It can go up to 20% in some sectors.
• The annual rate of departmental share is the same for the entire department. It shall be limited to a maximum of 2,5 %.
• The regional share rate set by the Regional Council of Île-de-France may differ from one department to another within the limit of 1%.

Calculation and amount of development tax

In order to calculate the amount of the development tax, the taxable area of the created construction by the annual value per m², and then multiply that result by rate voted by the local authority concerned by the tax.

Values per m² are updated on 1^er January of each year according to the latest construction cost index published by the National Institute of Statistics and Economic Studies (INSEE).

At 1^er January 2025, the latest construction cost index published by INSEE is that of 3^e quarter 2024, the 2143 index (index of 3^e quarter 2023: 2106).

For 2025, the values applied in the calculation of the development tax are:

• the annual value per m² is €930 (excluding Île-de-France) and €1,054 for municipalities in Île-de-France;
• the standard value of swimming pools shall be €262 per m² ;
• the standard value of outdoor parking spaces shall be €3,052 per location (up to €6 105 per location, subject to the decision of the local authority).

Report and pay development tax

You must report the elements necessary to calculate the tax at the same time as your property return, within 90 days of the completion of the work.

Go for this in your secure space on the tax website, tab “Real estate”. Use the accommodation declaration form.

If the amount of your development tax is more than €1,500, you can pay it in 2 installments: you will receive two payment documents to be paid within 90 days and then 9 months after the completion of the work.