I often go to work at NUMA. The ground floor is an open, free, and quite serious coworking space. You can upgrade to other floors and spaces for a fee but they are dedicated to startups. I might have a look at other solutions for you if that doesn’t fit, but I might need other informations if I need to handle the search for you. What is your field of work? Can you speak any French?
Anyway, here is the link to Numa below