France uses AI to detect thousands of undeclared pools

Even when it struggled at times to distinguish pools from solar panels, the artificial intelligence program did well enough to bring €10 million in tax revenues after sniffing out more than 20,000 undeclared pools from satellite images.

A software French tax authorities developed in cooperation with Google and Capgemini, a consulting company, has detected 20,356 undeclared private pools in total since the experiment began last October.

It scoured aerial images of nine regions across France – with most unreported pools found in Bouches-du-Rhône and Var departments on the Mediterranean coast and scenic Ardèche department just north of Provence.

French law requires the declaration of permanent pools because they boost property value. Owners pay taxes to local municipalities, with an average pool of 30 sq m (322 sq ft) taxed at €200 (the same amount in dollars) per year.

According to the French Federation of Pool and Spa Professionals, there are more than three million private pools in France, with 244,000 installed last year alone. The pool installation rush in France started even before the pandemic, which further reinforced the trend as more people worked from home.

The tax authorities will deploy the software nationwide in what they expect could bring €40 million in additional property taxes. It could eventually be used to find other taxable objects, such as home extensions, patios, and gazebos.

"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, a deputy director of the French tax agency, told Le Parisien, which first reported the news.

According to the paper, the error margin of the software is still too significant to find objects that are more difficult to identify than the blue rectangle of a pool – which the program still struggled to do. It sometimes misidentified solar panels as pools or failed to spot those in a shadow or partially covered.

While unrelated, the push to tax undeclared pools comes after a summer of severe drought – France's worst on the record – and calls to limit water waste.