France’s ‘garden shed’ tax: how to check if previous owners paid and what if they did not?

France’s ‘garden shed tax’ is due on many outbuildings and pools in France when they are constructed - and it can still apply if a previous owner failed to declare them but how do you check this?.

In general homeowners in France who build a structure of over 5m² on their property must pay a one-off tax known as the taxe d’aménagement. 

This tax is sometimes referred to as the ‘garden shed tax’ but its scope is broad.

It is levied on most structures that require planning permission or prior declaration subject to local regulations, including swimming pools, verandas, garages, solar panels, covered terraces, carports, certain solar or wind energy installations and - of course - many garden sheds.

Problems can arise when buying a property where such works were not properly declared. 

How can you find out if the previous owner paid the tax?

Firstly, permanent structures on a property that were built after requesting a permis de construire, or via a déclaration préalable de travaux from the marie, with their completion then properly declared to the mairie and tax office, and tax paid, should appear on the local cadastral maps.

These are not always supplied as part of the paperwork during a sale process, but anyone can request to consult them at the mairie. They can also be found online. 

Studying these, then, is a good precaution if you are wondering if a swimming pool, outhouse, extension etc was properly declared. 

The mairie should also keep records of past planning permissions or prior declarations that were received relating to the property.

Not all owners properly declare these works to the mairie and tax office in which case the new owners can find themselves having to pay payments they did not know was due, in addition to potentially receiving a retrospective property tax bill. 

These taxes are due even if the structure is not attached to the main home or used as living space.

However, there are time limits as to how long retrospective taxe d’aménagement can be recovered. 

In the case of structures subject to planning permission / prior declaration and that were never declared at all, this is to the end of the sixth year after the year of completion. If permission was obtained but completion was not declared to the tax office and the tax not paid, the period runs until the end of the fourth year following the one from when the permission was granted. 

In the case of structures that should have been subject to permission/declaration and where this was not done there is also the potential risk, for up to 10 years after construction, of the mairie taking a court case to order demolition, if it deems this necessary.

What if structures were not declared - is the new owner of home liable?

If a previous owner built a taxable structure without declaring it, the new owner may face consequences - particularly if the authorities become aware of the omission.

Indeed, since 2022, tax authorities have used satellite images and AI tools to detect undeclared works. In its first year alone, this led to the detection of 20,000 undeclared swimming pools.

It is not unusual for buyers to discover after purchase that a pool or veranda was built without permission and is missing from official records. 

In such cases, the local authorities may request regularisation and there may be a tax demand for the taxe d’aménagement that was not paid. The increased property value may also result in a retrospective increase in the taxe foncière bill for up to four years back (but only for any years in which you were the owner of the property). 

If so, then the added value represented by the construction that was not properly declared will also give rise to a proportional increase in future bills. 

Although legal liability partly lies with the person who commissioned and failed to declare the works, in practice the current owner may also be held partly responsible.

If in doubt, you can apply for regularisation via the local property tax office (centre des impôts foncier) for recently-built structures that were not declared. You should also contact your mairie. 

If you face paying extra tax, or even a demolition order, then it is possible to seek redress through the courts from the former owner, who may be held liable under article 1641 of the French Civil Code, which protects buyers against vices cachés (hidden defects) in a property. 

How can prospective buyers protect themselves?

Before buying, it is advisable to:

• Compare the property with cadastral maps and planning records (correctly declared structures should be shown)

• Ask the seller if they declared completion of relevant structures to the mairie and tax office and paid the tax

• Inform the notaire of any doubts you have about structures on the property - they can request proof that the structure has been declared and that taxe d’aménagement has been paid

Buyers may also ask the notaire to include a clause in the compromis de vente detailing who is liable for any undeclared works.