The workshop will take place at the IPhT-Saclay, in the Bloch auditorium, located just after the entrance of the building.
Practical information about the venue can be found at this link (the French version is more interactive than the English one).
A list of hotels can be found at that link. We recommend lodging solutions close to the IPhT (around Orsay, Ormes, etc.) which will reduce by a lot the transportation time to the venue. Coming to IPhT with public transports from the South of Paris (RER B + bus) takes about 1h at best.