French tax authorities using AI software have found thousands of undeclared private swimming pools, landing the owners with bills totalling about €10m.
The system, developed by Google and Capgemini, can identify pools on aerial images and cross-checks them with land registry databases. Launched as an experiment a year ago in nine French departments, it has uncovered 20,356 pools, the tax office said on Monday, and will be extended across the country.
Modifications to property, including adding swimming pools, must be declared to the tax office within 90 days of completion. As property taxes are based on the rental value of the property, improvements mean an increase in taxes. A typical pool of 30 sq metres would be taxed at about an extra €200 a year.
The tax office – or le fisc, as it is known – says it is now looking at using the system to spot undeclared annexes, extensions and verandas including permanent pergolas.
“We are particularly targeting house extensions like verandas, but we have to be sure that the software can find buildings with a large footprint and not the dog kennel or the children’s playhouse,” Antoine Magnant, the deputy director general of public finances, told Le Parisien newspaper.
However, the tax authorities’ technical team say they are not yet able to establish whether a rectangular shape on an aerial image is an extension or a tent, terrace or even tarpaulin placed on the ground.
In April it was claimed that the Google-Capgemini software had a 30% margin of error. Not only was it mistaking solar panels for swimming pools, but it was failing to pick up taxable extensions hidden under trees or in the shadows of a property. Tests are being carried out to perfect the technology.
“This is our second stage of research and will also allow us to verify if a property is empty and should no longer be taxed,” Magnant added.
France is believed to have about 3.2m private swimming pools and reported a boom even before the Covid lockdowns of 2020 and 2021, when there was a surge in installations as more people worked from home.
The public finance authority DGFiP said the AI programme would now be rolled out nationwide, potentially leading to €40m in new taxes on private pools in 2023.
The clampdown comes as French environmentalists have called for the banning of private pools after the summer heatwave sparked drought and water restrictions.
Julien Bayou, the national secretary of Europe-Ecology-the Greens (EELV), said the French needed “a different relationship with water”. He said that with drinking water supplies threatened, it was reasonable to consider limiting the use of water for recreational purposes. “The challenge is not to ban swimming pools, but to guarantee our vital water needs,” he said.
Mélanie Vogel, of EELV, insisted the party was not in favour of a pool ban, but added: “Because of inaction on the climate, the access to drinking water is threatened and we must restrict its use.”