Rockwool and Bouygues Construction join forces to transform the Parc du Robec, near Rouen

At the origin of this large-scale project, the social landlord Logeo Seine assisted by Bouygues Bâtiment Grand Ouest. The purpose of these renovation works is to improve the comfort of the inhabitants of this district, to achieve energy savings and to upgrade the district with modern and ambitious architecture.

Buildings, currently classified E for their consumption, must see their energy consumption halved and, by 2024, obtain a C energy label. To meet this challenge launched by the lessor and contracting authority Logéo Seine, Bouygues Bâtiment Grand Ouest, representative of the design-build consortium for the rehabilitation of the project, called on the expertise of ROCKWOOL, the world leader in stone wool solutions. After consultation, the installation of an innovative device for insulation from the outside on facades under metal cladding and reinforcement of fire protection were chosen with a method allowing a reduction in construction waste. .

This waste reduction is made possible thanks to Rockcycle, a 10-year-old ROCKWOOL service. Rockcycle offers a solution for collecting and recycling used panels and makes it possible to meet the challenge of recycling as well as fire safety, two major points for this 10-hectare site, which is currently one of the most remarkable in France.

During an on-site visit on May 17, 2022, Jérôme Cacheleux, Site Manager at Bouygues Bâtiment Grand Ouest, and François Habalou, Metal Box Product Manager at ROCKWOOL, explained that "ROCKWOOL and Bouygues Bâtiment Grand Ouest are committed, aware of the issues and environmental issues worked together and organized themselves to successfully recycle 30.000m² of dilapidated insulation”.

For energy transition and occupant safety, a solution: insulation

To respond to energy, circularity and fire protection issues, ROCKWOOL has established itself as a trusted service provider to the executive project management to ensure the thermal comfort of the 14 buildings with 645 housing units and the residence for the elderly La Belle Etoile (37 apartments). The Parc du Robec renovation project is a real challenge since it includes the rehabilitation of facades and the recycling of waste. A combination of solutions that make it an exemplary and pioneering site, a true figurehead for future rehabilitation projects.

Limit thermal bridges on the facade

Of the 30.000m² of facade surface to be renovated, nearly 17.000m² of insulation under metal cladding without flaps and 13.000m² of insulation under plaster have been deployed. This innovation was possible thanks to CERIB tests with Ecorock Mono which allows the reconstruction of unfavorable C+D on certain buildings.

This device allows an optimization of the application time because the rock wool solutions are not affected by the rain and do not require tarpaulin, but also a limitation to the maximum of the risk of thermal bridges as well as a durability of the system of insulation due to the format and density of the Rockfacade panels.

A challenge met by ROCKWOOL solutions to prevent the spread of fire

In addition to its durability, the device provides resident safety with excellent fire performance. Decrees of August 7, 2019 relating to the fire protection of residential buildings specify several regulatory requirements concerning the risk of fire spreading on the facade. ROCKWOOL products are designed to withstand temperatures up to 1000C°. It is with this proposal for a cladding solution "without grouping" and without contribution to the "C+D" of the facade of the buildings of the Parc du Robec that the challenge was won for the various actors of the site. Resident safety is enhanced by the excellent fire resistance of the A1 class incombustible insulation.

Recycling, a central concept in the renovation of the Parc du Robec

Each year, 46 million tons of waste are produced by the building sector. To face up to these challenges, several building players have not waited for the legislator and have organized themselves, such as ROCKWOOL with its Rockcycle service, which is celebrating its 10th anniversary this year. Last year, more than 1000 tonnes of stone wool, including 450 tonnes collected on site, were recycled.

The new Rockcycle service is adapted to the size of the site. It includes a pack with sorting instruction sheets, a removal request form and waste bags (“big bags”). It facilitates the sorting of the various waste related to the use of the products in an efficient manner on the construction site.

Within 10 days of the customer's request, ROCKWOOL comes to collect the waste from the site. Rock wool offcuts are then directly included in the production of new wool. The pallets are collected, tested, repaired if necessary and reused.

The ROCKWOOL production site in France, based in Saint-Eloy-Les Mines (Auvergne), has obtained four international certifications, all of which were renewed in 2021, for the implementation of its management systems linked to its approaches: quality (ISO 9001), environmental (ISO 14001), energy (ISO 50001) and finally health and safety (ISO 45001). These certifications bear witness to ROCKWOOL's commitment to the deployment of a dynamic of continuous progress within the framework of its sustainable development policy.

Rockcycle Reno

ROCKWOOL continues to expand its waste recycling program to all types of building and strengthens its offer with Rockcycle Réno. In addition to the recovery of old wools on energy renovation sites, this program intervenes as in the Parc du Robec where ROCKWOOL has joined forces with NPC Alizay, a local service provider which is equipped with a baler and packages the rock in bales to optimize storage and transport. NPC Alizay is responsible for the rental of 30m3 skips, rotations on the site and then responsible for collecting, compacting and shipping to Saint-Eloy-Les Mines the offcuts taken from the deconstruction.

The future site in Soissons (Hauts de France) will make it possible to increase the quantity of waste treated and to develop the Rockcycle program on a larger scale.

Sustainability at the heart of ROCKWOOL's DNA

A report is published each year by ROCKWOOL containing its sustainable development objectives. In 2021, for example, ROCKWOOL has committed to a series of measures to achieve its decarbonization objective of reducing its global absolute greenhouse gas emissions by one third by 2034, notably by providing for a rate between 50% and 75% of rock wool recycled on its lines in France and abroad. Another of these measures consists of reducing by 38% greenhouse gas emissions in the factory and by 20% greenhouse gas emissions over the entire life cycle outside the factory.

To achieve these objectives, ROCKWOOL France is going to build a new factory in Soissons equipped with high-performance, cutting-edge technologies, including an electric oven of an unprecedented size for ROCKWOOL. The operation of this furnace (electric fusion) is more energy efficient than a coke furnace (conventional fusion) and allows a reduction of around 70% in CO2 emissions, especially when electricity production is -even decarbonized.

For Jens Birgersson, CEO of ROCKWOOL: “Buildings are responsible for 28% of global and EU emissions alone and around 75% of buildings globally are energy inefficient. ROCKWOOL products play a key role in the fight against climate change by reducing energy consumption in buildings. The building insulation we sold in 2021 will continue to reduce the annual energy consumption of more than one million homes, for the life of the insulation. »

Coming from a natural and inexhaustible resource, fire resistant and infinitely recyclable, ROCKWOOL stone wool is one of the most effective and sustainable solutions in terms of thermo-acoustic insulation. These performances added to a lifespan of more than 55 years and perfect recyclability allow ROCKWOOL products to be respectful of the environment.

Key figures and dates of the Parc du Robec rehabilitation program

• Filing of administrative authorizations: February 2021
• Beginning of the roadworks : was 2021
• Final delivery planned before summer 2024
• Work budget: 22 M€
• 645 housing divided into 13 buildings from R+4 to R+18
• 1 residence for the elderly of 37 apartments
• Demolition of 20 dwellings to create an opening on the City

The actors of the project

• Client: Logeo Seine
• Design-build group:
  • Manufacturer: Bouygues Bâtiment Grand Ouest, leader of the consortium, execution of works, support for residents, organization, management and coordination
  • architects: Boucles de Seine Architecture and Fabri Architects o Urban planner: Atelier Lignes
  • Economist and Research OfficeAll State Corps: Economy 80
  • Landscaping: Architecture and Landscape Agency and Les Cocottes Urbaines