Nightwatchman Nabil Bekali, his girlfriend, Fatima Tahrour, face three to five years in jail if found guilty of manslaughter and unintentional injury, while Nabil's parents, Rachid et Fatima Dekali, face up to five years for flouting safety regulations.
There were 77 people staying in the hotel on the night of the fire, way over the legal limit of 62, and Nabil Bekali had not received the legally required training in fire prevention.
The blaze started after a row between the nightwatchman and his girlfriend, which concluded with Tahrour throwing clothes onto lit candles and storming off.
In court on Thursday she claimed to have left before the alarm went off, a story that was challenged by presiding magistrate Alain Alcufrom.
Eight years after the blaze, Jean-Baptiste Eyraud from housing campaign Droit au logement, blames the tragedy on overcrowding and poor security standards.
"Today, more than 45,000 people are living permanently in hotel rooms," he told RFI. "The government could choose to put people elsewhere: private apartments are a bit more expensive than social housing but they are much less costly than hotels. The state could also requisition unused buildings. There are a lot of those in our country. Finally, it could also boost its overall use of social housing and public spaces to accommodate the homeless."