French ecological architect Vincent Callebaut has won a competition to redesign ancient thermal baths in the Savoyard town of Aix-les-Bains, France.

Dubbed "Ecume des Ondes" (Foam of Waves), Callebaut's proposal features a many-storied, heavily foliaged structure with waveform green terraces.

Other elements of the spa centre include a retail galleria dedicated to wellbeing, a rooftop restaurant with an aquaponic urban farm, and a viewing centre for the site's Roman ruins, as well as a number of residential sky villas.

The residences – according to Callebaut – will also be "covered with more than 25,000 plants, shrubs, and endemic trees", all producing "more energy" than they consume.

"It's about both preserving the best of each identifiable era to build the future of Aix, and tracing the evolution of thermal practices related to the progress of medicine," Callebaut explained.

The thermal baths – once a leisure playground for Europe's elite in the Belle Époque period – have been out of commission since 2008.

The future wellness facility is expected to serve as a sustainable public park and restore interest in the town's cultural history.