In Nancy, an eco-friendly college to save energy bills

The brand new building had its first entrance in September. It is the first "positive energy" college in the Grand Est region: it consumes less energy than it produces, a significant criterion now for the department of Meurthe-et-Moselle, which manages 66 public colleges and 13 private.

Due to soaring energy prices, the department's gas bill has jumped by 7 million euros, that of electricity by 12 million euros for 2023, i.e. "the cost" of construction "of a new college", explains the president, Chaynesse Khirouni.

Compared to the previous building, this one should therefore make it possible to achieve "90% savings in heating" and "50% in electricity", specifies Ms. Khirouni, adding that for the moment, the department "maintains its investments: the education is the priority".

Straw, wood and solar panels

A large building with a black front, this college was built largely with biosourced materials, explains Delphine Montrelay, engineer who designed the building. The structure is made of wood and the insulation is made with compacted straw.

Photovoltaic panels have been installed on the roof. To regulate the temperature inside, the large bay windows are triple-glazed and all have adjustable blinds that let in sunlight but not heat.

A “double flow” system makes it possible to renew the air in the building by sucking it in from the outside: then a central unit heats or cools it depending on the season, adds Ms. Montrelay. In the very bright classrooms, no air conditioning: "We ventilate" thanks to this system; And when it's hot, wooden ceiling fans help cool the air.

As a result, it is neither cold in winter in the building, connected to the district heating network, nor too hot in summer.

Silence in the halls

Another advantage that delights the teachers and the 360 ​​students: wood fiber panels provide welcome sound comfort. Despite the large bay windows of the CDI, Deïssiana Labonté, 11, remarks that "we hear nothing" in the rooms. "We can concentrate better" because "we hear less noise from outside", agrees her classmate sitting next to her, Lola Wenck.

A more pleasant setting for teachers: Delphine Chappe, 41, is a physics and chemistry teacher and does not regret the old college, an old building with "hateful thermal conditions" where "we were too hot in summer".

Here, it's "quieter" and "it resonates less, we have less need to force our voices", underlines Ms. Chappe. She says she has "less headaches" in the evening at the end of her school day, thanks to this "more serene setting" for teachers and students.

The teacher also welcomes the fact that she and her colleagues have been included in the construction project, "to take into account" their "needs and constraints": "we are there every day, it is normal to associate ourselves" . She also asked to have “enough” electrical outlets in her classroom, necessary for the scientific experiments she has her students do.

As for the other existing establishments, the department of Meurthe-et-Moselle launched in 2012 a policy of energy renovation works of 55 colleges, in particular to renew the boiler rooms, connect the buildings to the heating networks or even insulate them. Total cost of the operation: nearly 170 million euros.