Eiffage SA

04/07/2023 | Press release | Distributed by Public on 04/07/2023 04:06

Eiffage Construction participates in the #NouveauCHURennes project and places wood at the heart of the construction of the 'tertiary' building

The "tertiary" building will be developed over 6 levels (6,531 m² of floor space) and will include office space that can be adapted to needs: offices for one to four people, open spaces, meeting rooms, relaxation areas and various common areas (changing rooms and showers).

The existing building was deconstructed, following a circular economy process.

The major element of this prefabricated construction is wood (100% of the wood batch is designed and treated by Savare). The 320 m3 of glued laminated timber post and beam framework, the more than 6,500 m² of CLT (Cross Laminated Timber) floors and the development of the 3,770m² of timber-framed facades are all produced in the Savare factory. The prefabrication saves a considerable amount of time in the implementation on site. The two concrete cores that integrate the lifts and staircases.

The architecture proposes a mix of wood and steel exterior cladding. Among the design choices, we can also note

  • The mixed wood/aluminium exterior windows equipped with reduced solar factor glazing to improve summer comfort,
  • The modular partitions separating the offices allow the flexibility of the spaces according to the needs;
  • The acoustic treatments in the false ceilings are partial, leaving room for the visual aspect of the wooden structure, in a spirit of frugality (less material).

This project is part of the Eiffage Group's ambitious environmental approach, aiming for BBCA certification. With regard to the 2020 Environmental Regulations (RE2020), the Life Cycle Analysis of the building shows that the project is already at the level of the 2028 environmental objectives on the carbon indicator for construction: 528.66 kg eq CO2 /m², i.e. -38% compared to the RE2020 regulatory threshold for construction. In addition, 100 kg/m² of bio-sourced products were used in this operation, thanks in particular to the massive use of wood in all its forms.

From an energy point of view, the thermal balance sheet provides for a 20% reduction compared to the RE2020 by relying on a reasoned choice of technologies that are certainly tried and tested, but chosen for their energy performance and minimal environmental footprint: heat/cold production by reversible heat pump (radiating panel emitters); double-flow AHU ventilation; LED lighting with presence detection; centralized technical management system; photovoltaic panels.

With regard to biodiversity, it was decided to retain the trees and nesting boxes currently present on the Villejean site. A green roof will be added, as well as a green space in the ground and permeable exterior coverings for the road areas. This will improve rainwater management.

The work, which will last 10 months, should begin in the spring of 2023 with a view to delivering the first phase in February 2024. We wish our teams every success in meeting this challenge!

Architect / Engineering: CRR Architecture and Oteis
General contractor: Eiffage Construction
Co-contractor : Savare