Du Besset-Lyon transforms former sanatorium into Clermont-Ferrand School of Architecture

Paris studio Du Besset-Lyon has converted and extended a 1930s sanatorium to create a new school of architecture in the French city of Clermont-Ferrand.

Located on the border between a residential neighbourhood and a large area of parkland, the building was originally a medical facility for treating long-term illnesses. Treatments focused on exposing patients to plenty of sunshine and fresh air.

Having gradually fallen into a state of disrepair, the building was designated for renovation as it was protected by heritage status.

France's Ministère de la Culture et de la Communication, which operates 20 architecture schools around the country, invited Du Besset-Lyon to repurpose and expand the existing structure for its new occupants.

The narrow south-facing building that previously housed the sanatorium was retained and its inner masonry structure was bolstered with a steel frame to ensure it complies with contemporary seismic regulations.

On the building's north side, the architects added a bulkier extension that contains auditoriums, exhibition spaces, a library and a cafeteria.

The addition continues the simple visual language of the original building and aims to retain its connection with the surrounding landscape – both qualities that the architects regarded as a positive example for the students.

However, while the sanatorium isolated patients and provided maximum exposure to the southern sun, the extension offers plenty of opportunities for interaction and controls the amount of light reaching the interior.

"The sanatorium took advantage of the south orientation and separated the occupants by gender and wealth," architect Dominique Lyon told Dezeen. "The new construction hosts young people full of energy who are hypnotised by screens. They need to mingle and keep out of the sun."

The addition contains the main entrance, above which the architects installed large mirrored panels that function as a heliotrope to amplify light and views.

"Symbolically the patients entered from the north to be directed toward the sun, hoping to be cured," Lyon explained. "Since this building has radically changed its functions, we wanted the sun to illuminate the north facade where the students enter."

The building's southern elevation has been adapted so that, instead of rows of patient rooms, it now contains circulation areas that provide an insulating barrier to protect the rest of the interior from overheating.

"The south facade of the school is transformed into a promenade that gives views on the panorama and states the territorial stature of the building," Lyon added. "This 100-metre circulation constitutes a buffer zone for the studios that face north."

The school's main social spaces are accommodated on the ground floor, where a large foyer is flanked by a multipurpose hall on one side and the library on the other.

A short set of steps leads to a landing from which a curving steel staircase ascends to the levels above.

The landing accommodates a cafeteria space positioned in front of glazed doors that open onto a bridge connecting the school building with the surrounding parkland.