Understanding the Development Tax in France

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Planning to build a garden shed, a swimming pool, or extend your home? You may be liable for a local levy known as the development tax. Here’s what it covers, how it’s calculated, and whether you might be eligible for a reduction or exemption.

What Is the Development Tax?

The development tax is a local charge collected by municipalities, departments, and in the Île-de-France region, also by the regional council. It helps finance public infrastructure such as roads, schools, and public transport, all of which are necessary to support new developments.

This tax applies when you carry out certain construction or installation projects.

Which Projects Are Taxable?

You are required to pay the development tax if your project involves any of the following:

  • New construction, reconstruction, or extension of a building,

  • Installation of structures like pools or mobile homes,

  • Conversion of a building from a non-taxable use to one that is taxable.

The tax applies once you obtain any of the following planning authorizations:

  • Building permit,

  • Development permit,

  • Prior declaration of works.

Note: Even if work is performed without proper authorization or goes beyond what was approved, the tax may still be owed.

What Areas Are Taxed?

The tax applies to any enclosed and covered floor area of more than 5 square meters, with a ceiling height of at least 1.8 meters. This includes attics, cellars, and annexes like garden sheds or verandas, whether fixed or removable.

Structures that are open to the outside, such as pergolas or terraces, are excluded from taxable surface area. However, certain installations (e.g., pools, parking spaces) are subject to a flat-rate tax, even if they’re not part of the covered floor space.

What Is the Tax Rate?

The development tax consists of two mandatory components:

  • Municipal rate: Generally between 1% and 5%, though it can go up to 20% in areas where significant public infrastructure is needed or for environmental preservation.

  • Departmental rate: Capped at 2.5% and uniform across the department.

In Île-de-France, a regional rate is added, which varies by department.

How Is the Tax Calculated?

The formula for calculating your development tax is:

Taxable surface × standard value per m² × applicable rate(s)

The standard value per m² for 2025 is:

  • €930 outside Île-de-France,

  • €1,054 in Île-de-France.

Some items like pools or parking areas use fixed values:

  • Pools: €262 per m²

  • Outdoor parking spots: €3,052 each (up to €6,105 if the local authority decides)

Tip: A government-provided simulator can help estimate your tax in five simple steps.

Possible Deductions and Exemptions

Reductions (Allowances)

A 50% reduction applies to:

  • The first 100 m² of a primary residence,

  • Industrial or artisanal buildings,

  • Subsidized housing,

  • Warehouses not open to the public,

  • Covered commercial parking lots.

Automatic Exemptions

Some projects are exempt by law, including:

  • Constructions ≤ 5 m²,

  • Rebuilding identical structures destroyed by disasters (within 10 years),

  • Projects required under risk prevention plans (e.g., for floods or mines).

Discretionary Exemptions

Local authorities may grant optional exemptions for:

  • Small non-professional greenhouses, dovecotes, or sheds ≤ 20 m²,

  • Part of a primary residence financed by a zero-interest loan (PTZ),

  • Historic buildings listed as monuments.

Declaring and Paying the Tax

The declaration and payment process depends on when your planning permission was filed. The following applies to applications submitted since September 1, 2022.

Declaration

Log into your secured “Biens immobiliers” space at impots.gouv.fr and declare:

  • Within 90 days after work completion for buildings < 5,000 m²,

  • Within 7 months of authorization for projects ≥ 5,000 m².

Payment

For projects under 5,000 m²:

  • If the tax is under €1,500, you’ll receive a single payment request about 90 days post-completion.

  • If the tax exceeds €1,500, payment can be split into two:

    • First installment: 90 days after work ends,

    • Second installment: 6 months after the first.

For projects of 5,000 m² or more:

  • Two advance payments are due:

    • 50% in the 9th month after authorization,

    • 35% in the 18th month.

  • These are deducted from the final tax amount.

Want to know more?
Check official updates and simulate your tax on service-public.fr or consult your local planning office for advice tailored to your location.