Recycled concrete building, hemp concrete facade, mud brick walls… Initiatives to build housing or public buildings in a more environmentally friendly way have multiplied in recent years in Ile-de-France.
An approach that the Paris Region Institute (IPR) wishes to highlight in its notebook entitled “Building circular planning”.
"It is a collection of good practices which shows that we can do otherwise, such as reuse, recycling of materials or the transformation of existing ones, to avoid demolishing for example, points out the author of the notebook, Martial. Vialleix, urban planner specializing in territorial ecology at the IPR.
This is called circular development.
Today, this often remains in the field of experimentation, it requires a lot of effort and requires the establishment of channels, sorting and storage platforms, but there is a real proliferation of projects that can make you think.
Read alsoWhat happens to construction waste?
In Gennevilliers, we recycle them
Currently, approximately 32 million tonnes of construction or public works related waste is produced annually, of which 20 million is excavation soil.
Over its entire duration, the Grand Paris Express site will represent a cumulative total of 45 million tonnes of excavated material.
Finding an alternative to dumping, when possible, is therefore enormous.
Rehabilitation and reuse at the Reuilly barracks in Paris
Several materials from the Reuilly barracks (12th century Paris) were taken and reused, sometimes on the site, such as these solid wood cabinets or certain radiators.
Paris Habitat TV video screen capture
In Paris, the former Reuilly barracks (12th century) has been converted into housing, including 600 social housing units in total, by Paris Habitat.
"This is in itself a virtuous model, because we keep the existing buildings, which avoids excavating land", continues Martial Vialleix.
But that's not all.
Parquet floors, radiators, beams, lighting, cupboards or stairs have been recovered and reconditioned by Rotor, a Belgian pioneer agency in this field.
Recommendations for reuse have made it possible to integrate certain materials into new projects: reused cupboard doors, sanitary block partitions transformed into worktops, paving, etc.
A hemp concrete building in Trilport, in Seine-et-Marne
Trilport (Seine-et-Marne). The 45 social housing units in the Ancre-de-Lune eco-district will have insulation using hemp concrete, as on the facades of the building on the left. LP / Alexandre Arlot
Bio-based products are at the heart of the Ancre-de-Lune eco-district, a 450 housing project in Trilport, in Seine-et-Marne.
A first building of 45 social housing units is emerging from the ground.
Built by foyer Rémois - ESH (social enterprise for housing), with the support of Grand Paris Aménagement and the municipality, it has the particularity of having a hemp concrete facade, composed of chènevotte, hemp straw and lime.
The hemp used comes from Planète Chanvre's defibrating plant, located near Coulommiers (Seine-et-Marne) and the hemp is grown 50 km away.
This material is not only a very good insulator, but does not emit pollutants.
In the Yvelines, a mud brick school in Villepreux
In the Thomas-Pesquet school group in Villepreux (Yvelines), dividing walls between the classes were erected in mud bricks.
Joly & Loire architecture agency
The Hauts-du-Moulin school group, renamed Thomas-Pesquet, in Villepreux, in the Yvelines, is special.
The classrooms are separated by walls made of earthen bricks from the Grand Paris Express construction site and linked together with earthen mortar.
Prefabricated in the Dewulf brickyard in Allonne (Oise), approximately 80 km from Villepreux, they have several virtues: humidity regulation, sound insulation, etc. The architect of the project is participating in the creation of a brick manufacturing plant in soil from the Grand Paris Express construction sites in Sevran (Seine-Saint-Denis).
La Fabrique Cycle Terre should open in September.
Objective of 40% reuse of spoil in Arpajon and Ollainville, in Essonne
The Belles Vues eco-district will be created in Arpajon and Ollainville (Essonne).
Several workshops are organized with the inhabitants upstream.
In Essonne, the Belles Vues eco-district, in Arpajon and Ollainville, which provides for 1,000 housing units over 56 ha in 2026, is framed by a sustainable development charter which sets a target of 40% in situ reuse of the excavated material produced during the construction site. .
It also prescribes the use of local resources and businesses, local know-how and requires, on a financial level, that the materials used on the site be manufactured for at least 20% of the budget within 100 kilometers around the site, 50% of the budget within 1000 kilometers and 95% in Europe.
In the Hauts-de-Seine, selective deconstruction for the Châtenay-Malabry eco-district
In the future LaVallée eco-district in Châtenay-Malabry (Hauts-de-Seine), around 2,200 housing units as well as offices and activities are planned on the site of the former Central School, by 2027 (date planned before the Covid) .
For Martial Vialleix, the project is exemplary in terms of circular town planning: the concrete resulting from demolitions, recycled into aggregates, is used at 30% to construct the new buildings.
The RéaVie association intervened upstream of the demolitions to select what could be recovered and thus reuse 120 tonnes of materials (doors, toilets, cables, etc.).
Part of the land needed to level the land comes from a site in Clamart, located 6 kilometers away.
Reuse of concrete in the Gagarine operation in Romainville, in Seine-Saint-Denis
This urban renewal project is a pioneer in the area in terms of the reuse of materials.
For the Gagarin urban renewal operation in Romainville, in Seine-Saint-Denis, a diagnosis was carried out in 2017 on the reuse of concrete on housing bars in order to consider its possible reuse on road and public works. public spaces, as well as the use of railings to create fences.