Please reuse your building after use

“My daughter couldn’t understand why I was taking her to the Batitec, the second-hand store set up to sell all the materials, tiles and timber from demolished buildings,” says Valérie Doubinsky, Project Leader of Grenoble-Alpes Metropole’s Circular Economy in Waste Department. “But when we got there she spotted some wood she could re-purpose to make just the kind of display unit for her guitar she’d been looking for.”

On a personal level, Doubinsky was pleased her daughter found the trip useful in the end. From a professional perspective, she was thrilled to see yet another slightly hesitant shopper become an enthusiastic reuse consumer.

“Like my colleagues who turned the pieces of wood they bought at the store into kitchen tables and garden benches, it is interesting to see how you can imagine different things to do with old materials that suit you much more than if you’d bought a standard new item,” she enthuses.

These individual purchases might seem small scale. The reality, however, is that they represent the biggest example of citizen participation in one of the largest deconstruction and reuse urban development projects ever undertaken in Europe.

Without the interest and ingenuity of the residents, builders and architects who bought a total of 320 tons of building materials from the store, Grenoble-Alpes Metropole’s grand green experiment would undoubtedly have failed.

Incineration and landfill can no longer be the default

For some years, the metropole had been looking for ways to embed circular economy thinking and action into its construction industry. Not only because raw material extraction, manufacturing and construction account for up to 12% of national greenhouse gas emissions in Europe and over 35% of the EU’s total waste generation. But also because 70% of building waste must now be recovered in France, by law.

The site of the Cadran Solaire is a former military hospital inaugurated in 1911 so we are on a long term evolution with this site which is going to host housing and university buildings
— Bertrand Spindler, Mayor of La Tronche

“There is very little knowledge in the industry about its responsibility for managing waste or the valorisation of waste,” says Doubinsky. “It’s also difficult to explain and try to change behaviour when reintroducing large quantities of waste back into the economy is thought to be time-consuming and costly.”

The metropole’s lightbulb moment was, she says, realising that, “We need large-scale references for reappropriating waste back into construction if the concept is to go mainstream. Otherwise we will never know if the perceived disadvantages are real, what methodologies and tools are needed and what the ecological and social benefits are.”

At the time, a huge strategic urban renewal project was underway in the municipality of La Tronche on the site of a former military hospital. Could this provide an opportunity for an experiment targeting the methodical deconstruction of a complex of buildings and the promotion of short circuits for the reuse and sale of materials? Yes it could!

When the metropole’s proposal won the Urban Planning and Circular Economy prize awarded by the French agency for ecological transition (ADEME) in 2017, the project gained the funding, credibility and momentum to get underway.

This was not, however, before the local team had created a wider vision for the project, which was named Cadran Solaire after a famous sundial on one of the site’s preserved buildings.

We have to evaluate this reuse approach from the point of view of carbon neutrality, costs and jobs and then compare this to a classic demolition
— Renzo Sulli, Vice President, Urban Development and Renewal, Grenoble-Alpes Metropole

The city had determined that citizens would be involved at every stage and the site open to all local actors. And that improving biodiversity and local professional practices and skills would be important goals.

Altering, refinishing, resizing and reusing materials to slash emissions

Partnering with the commercial, academic and state co-owners of the site, the metropole entrusted the demolition of four of the site’s 13 buildings to Aplomb/Ecomat 38, a specialist in the selective removal and reuse of materials.

“We give a second life to materials that are no longer waste,” says Bruno Jalabert, Co-Director of Aplomb. “One of the first steps is to clean up the buildings, that is, to empty them of furniture, furnishings and materials. Secondly, the inert materials such as timber, steel and tiles are deconstructed and carefully sorted for reuse.”

The city becomes a source of reusable materials for a circular economy
— Bruno Jalabert, Director, Aplomb/Ecomat 38

Salvageable material is reused in the new buildings being constructed on the three-acre site, which is being transformed into a mixed-use eco-district combining housing, services and research facilities and providing public spaces around a large urban park.

Over 50 tons of tiles and 75 tons of wood have been earmarked to enrich the landscape of the neighbourhood as remodelled urban furniture, from gabions to garden structures.

Creativity extends to the remains of buildings too, with fragmented spaces turned into outdoor gardens and old basements into rain basins. Where recovered materials were in such bad condition they couldn’t be reused, workshops were set up to demonstrate their upcycling potential.

Salvaged electrical equipment was reclaimed, repaired and given a second life
Old doors were sold for upcycling into tables, benches and shelves
The Batitec store sorted and sold 320 tons of reclaimed materials

The second-hand shop inspiring staff, citizens and professionals

The fact that these workshops were held at the Batitec, which was open from March to July 2021, brings home its central role in the Cadran Solaire project as a source of information and inspiration for all-comers as well as a shop.

Here people can take their pick of materials and items such as window frames and cabinets, radiators and doors, light switches and sinks. Although things like this represent the biggest carbon saving, they have traditionally been considered unrecyclable. At the Batitec they went down a storm.

By inspiring people to turn taps into coat racks and doors into light structures, these interior products accounted for 20% of the store’s sales. This success clearly had a lot to do with shoppers’ ability to think outside the box. It also, no doubt, had something to do with the store’s enthusiastic and environmentally-minded sales consultants.

Like others recruited to work at the site, many were out of work because of the pandemic and had the time and commitment to make a significant difference to the success of the project.

Take Florian Ruppert, who was in charge of dismantling of the buildings. He says, “at the beginning it was for three weeks… now it’s been three months. It’s more a question of conviction than money!”

Serving the recovery sector through creativity is a real philosophy for me
— Augustine Bey, Artist and Batitec Sales Consultant

For artist and Batitec sales consultant Augustine Bey the job was attractive because, “it’s not only about creating but also adapting, making something new out of something existing is very stimulating. If I have a personal ambition it’s to show people that they can make things with their hands to consume differently.”

Unprecedented material recovery and emission reduction

“The Batitec was a real bet!” says Doubinsky. “It could have been a failure because selling 320 tons of reclaimed material is a big ask. But it has totally exceeded our expectations.”

In fact, the results from the Cadran Solaire operation as a whole were even better than expected.

Having set itself a target of recovering 85% of all materials, 15% more than is required by law, the project actually achieved 98%. The results also showed savings of 40% on the final costs, linked to the cost of waste avoided by reuse in situ, compared to conventional demolition and disposal and a reduction in CO2 emissions estimated at 373 tonnes of carbon equivalent.

“I also think the project has started to persuade the construction industry of the technical and economic feasibility of the project’s circular economy approach,” says Doubinsky. And this mindset shift looks set to continue now that this particular project’s work has come to an end.

We have started to change attitudes and practices in the construction industry
— Valérie Doubinsky, Project Leader of Grenoble-Alpes Metropole's Circular Economy in Waste Department

Working groups have since been set up for public building owners interested in implementing the new practices. Another shop like Batitec is already up and running. And architecture students have installed a prototype materials yard at one of the city’s waste collection centres where people can drop off and pick up free construction materials.

It certainly seems that word is spreading across the city, which, in the words of leading architect and environmental activist Duncan Baker-Brown, we need to think of “as material stores for the future.”

Cities dream, act and lead our future. This example from Grenoble Alpes Metropole is one of the finalists for the Eurocities Awards, in the category ‘Lead together – scalable solutions for positive climate impact’. The winners will be announced on 9 June 2022 during the Eurocities Conference.

Tiphanie Mellor