An icy mist bathes Bully-les-Mines, a town in Pas-de-Calais surrounded by slag heaps. Seated in her kitchen, Sylviane Niebojewski, 60, caresses her old miners' house, recently "refurbished".
A resident of the city "since always", she knew the settlements there "without bathroom or central heating", long heated by coal. Then this pavilion formerly "difficult to heat".
"We had a very small radiator in the kitchen, nothing in the bathroom, a huge frozen hallway. In winter we were frozen, even pushing the heating to 22-23°C. I also lit a kerosene stove “, she recalls.
Since 2021, and the rehabilitation carried out by the lessor Maisons et Cités, "with the thermostat at 19°C, we are hot, our gas consumption has dropped by 40%", she rejoices.
This represents "a saving of 50 euros per month, really welcome", for a couple with resources of around 1.100 euros, allowing them to "go on vacation a little more" or enjoy some leisure.
The construction site forced her to move for six months to a neighboring house, like the majority of the tenants of this century-old city, renovated as part of the commitment for the renewal of the mining basin (ERBM).
Initiated in 2017, this policy provides for the renovation of 23.000 thermal colanders over ten years, accompanied by a "requalification" of public space, and actions for employment. It aims to repair this territory of 1,2 million inhabitants, with record poverty rates and dilapidated settlements, even if partially classified as a UNESCO World Heritage Site.
Estimated at 2 billion euros, the thermal rehabilitation is financed by two social landlords, largely subsidized, in particular by the State (100 million), the Region (30 million) or the intermunicipalities (70-80 million).
"We take houses classified E, F, G, towards a label C or BBC (low consumption building)", summarizes Jean-François Campion, general manager of Maisons et cités, manager of 90% of the accommodation.
Each dwelling is "redone from floor to ceiling": the walls, cured, are lined with 12 cm insulation, the coverings, doors and windows replaced, partitions knocked down. The rent "may change slightly", around twenty euros for a rent of 400.
The ERBM has made it possible to double the pace of renovations, "prioritize the most fragile cities", and "go further on the bouquet of works", greets Marie Cornillon, deputy general manager of the second lessor, SIA Habitat.
A precursor project: the "Climate and Resilience" law, passed in 2021, will prohibit the rental of classified G accommodation from 2025, and F in 2028.
In France, 5,2 million main residences were "energy sieves" in 2022, according to the National Observatory for Energy Renovation. The social park remains the best off: 9,5% of F/G labels, against 18,8% for the private sector.
"Urgency to act"
In the former mining basin, halfway through, at the end of 2022, around 7.000 mining dwellings were rehabilitated, and more than half of the construction sites launched, according to several sources.
Donors and elected officials recognize a "slight delay", linked to the health crisis or to "tensions" in the construction trades.
But "the commitments will be kept", promises the prefect of Hauts-de-France, Georges-François Leclerc, who points to "the urgency to act", to "support" households, "maintain" this unique heritage, and "respond to ecological issues.
From Béthune to Valenciennes, the inhabitants interviewed by AFP mostly welcome the work carried out. Like Claudie Trifi, 58, happy to be rid of her old damaged frames, or her bare roof, "with nothing between the ceiling and the tiles".
It is "much more comfortable, economical, modern", also rejoices Christelle Cauvez, 49, daughter of miners.
Everywhere, dazzling vermilion facades and fenced gardens contrast with the faded bricks of the neighboring houses.
Those waiting their turn are often impatient. "Renovate? It's time! In the summer, we live in an oven. In the winter, I sleep in a sweater", loose in Lens Emilia Lequien, 41 years old. She fears "the explosion of prices" of gas, she who "already leaves 2.500 euros" there annually.
With the isolation from the inside, imposed by the Unesco classification, "it's smaller, the furniture no longer fits", regrets however, in a neighboring street, Micheline Fruchart, 75 years old.
A few rare inhabitants deplore them "poor workmanship", mainly in the first renovated cities. President of a collective of inhabitants in Hornaing, Jacky Saraïs had to "fight" with inhabitants and elected officials, to have the defects of around fifty dwellings repaired.
"We suffered the plasters", but the problems are "almost solved", slices the mayor Frédéric Delannoy, president of the community of communes of the heart of Ostrevent.
By attacking "quickly and strongly" the "most degraded, relegated" cities, this policy fights against "the feeling of abandonment" felt locally, salutes his counterpart at the gate of Hainaut, Aymeric Robin.
Even if, with the energy crisis, "the expected gain in purchasing power turns into a shock absorber".
Hemp concrete, wood wool: donors have also "experimented" with biosourced materials. But only on a "fraction" of volumes. A regret for Mr. Robin: "we could have gone further" to find "innovative, ecological processes" and "quickly duplicable".