The Grand Bain project was born from the need of the entrepreneurs and the support team of the Ouvre-Boîtes 44 to have a place to gather and the desire to open up to the public. L'Ouvre-Boîtes 44 is a solidarity company that reinvents the world of work and develops the local economy. The Call for Projects of the #15Lieux à réinventer launched by the City of Nantes came at the right time. The building of the former bathhouses appeared as the ideal place to realize this project of third-place, a multi-purpose place open to a varied public. In June 2018, the people of Nantes made it possible to make this project a reality by voting in majority for the Grand Bain project (called at the time «La Coopérative»).