New high school in the Clermont urban area

Eiffage is building a new high school in the Clermont urban area, under a design and build contract. Constructed using wood and straw, and with facades made of Volvic stone from the Massif Central, the building will meet high performance (E4 C2) standards.

Main project's drivers for reducing the greenhouse gas (GHG) emissions

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Energy and resource efficiency

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Energy Decarbonisation

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Energy efficiency improvements

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Improving efficiency in non-energy resources

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Emission removal

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Financing low-carbon issuersor disinvestment from carbon assets

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Reduction of other greenhouse gases emission

Project objectives

Construct a building that provides maximum energy performance and minimum carbon impact (E4 C2 performance – maximum level - E+C standard - Demonstrate the building’s energy performance and promote development of these solutions.

Detailed project description

Project carried out under a design-build contract. Below are the main members of the consortium having contributed to the design, Eiffage Construction being the lead contractor:

– CRR Architecture

– Eodd

– Sylva

– Ingerop

– Ecib

– Eiffage Energie Systèmes


The technical high school will accommodate 1,000 students and provide housing for 8 members of staff.


Efforts made in terms of the thermal design of the building’s outer skin and reduced energy requirements will enable the project to meet exemplary “passive” building performance standards.

The building will benefit from “100% renewable energy” with the exclusive use of wood for heating purposes (wood pellets) and all electricity consumption being met by the photovoltaic installations.

Thanks to the massive use of bio-sourced materials, the building will provide tangible carbon storage, which will drastically reduce its carbon impact.


Concrete base made from low-carbon concrete supplied by Vicat.


The straw-insulated wood frame walls are manufactured by Savare, a subsidiary of Eiffage Construction that specialises in wood construction (creation of a workshop close to the site to assemble the wood frame walls (MOB) and limit the carbon footprint of transportation). The straw is supplied by a farmer in Limagne.

The glued laminated wood structure uses a Douglas fir species supplied by Eurolamelle. The CLT walls and floors (Douglas fir) are being supplied by Piveteau.

The solid wood (Douglas fir) is being supplied by the Combrailles sawmill.

All the framework, structures and wooden floors are manufactured and installed by Eiffage Construction Auvergne.


Particular attention has been paid to the choice of products / suppliers / subcontractors in order to meet carbon objectives. This is the case in particular in terms of traceability of origin for the structural timber (92% from the Massif Central, 100% from France), straw (100% from the Limagne), and lava rock (100% from Volvic).


Quantity of bio-sourced materials: 148 kg/m² (compared to 36 kg/m² to achieve the level 3 bio-sourced buildings label for educational buildings, see


“Reforest Action”: 2,000 trees replanted

Photovoltaic production: installation of 2,000 m² of panels assembled in France

Wood pellet boiler

High performance insulation using straw (R = 7.10m².K/W)

Recovery of rainwater for use in toilet blocks.

Emission scope(s)

on which the project has a significant impact

Scope 1

Direct emissions generated by the company's activity.

Scope 2

Indirect emissions associated with the company's electricity and heat consumption.

Scope 3

Emissions induced (upstream or downstream) by the company's activities, products and/or services in its value chain.

Emission Removal

Carbon sinks creation, (BECCS, CCU/S, …)

Avoided Emissions

Emissions avoided by the activities, products and/or services in charge of the project, or by the financing of emission reduction projects.

Scope 1-Worksite emissions.

(lower thanks to the mobilisation of local players to reduce transport requirements).

Quantification: 265.9 tCO2eq.


Scope 3 – Upstream: Use of low-carbon concrete, mixed wood/concrete structure, particular attention paid to the choice of products / suppliers / subcontractors to meet carbon objectives

Downstream: E4 labelling (positive energy building):

Good insulation, in situ energy production.

Quantification :

12,120 tCO2eq. over 50 years of operation, i.e. 242.4 tCO2/year on average. (i.e. 15 kgCO2eq/year/m²)

A C1 building (“conventional” scenario today) with similar characteristics would have emitted approximately 28,126.4 tCO2eq.


Emission absorptions 

Quantification : 50 tCO2/year


Avoided emissions : Compared to a building with C1 certification

Quantification : 320 tCO2/year, or over total lifetime 16,006.5 tCO2eq.

Calculation carried out according to E+C- standard not taking into account dynamic LCA.

Operating emissions are mainly related to:

– primary energy consumption (RT use): 10,486 kWhep/year, including energy production of 9,870 kWhep/year for self-consumption (EF: 45 gCO2/kWh for photovoltaics), the rest on the network (EF: 60 gCO2/kWh)

– heating and hot water: 100% biomass (wood pellet boiler) (EF: 0.027gCO2/kWh PCE), instead of a conventional solution (0.243 gCO2/kWh PCE)

Forest planting: The calculation described here is based on assumptions made by the Ecotree organisation: we take their value of 25 kgCO2eq/year average absorbed by a tree (it being acknowledged that this value varies throughout the life-cycle of the tree depending on age or external factors). It is important to keep in mind that the carbon storage calculation is approximate and provides more of an estimate than a comprehensive value.

Key points

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Invested amount

Total investment by the AURA Region amounts to €57.5 million

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Project localisation

Design: March 2019
Execution: August 2020
Delivery: July 2022

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Project maturity level

Clermont-Ferrand (Puy-de-Dôme)

Project maturity level

Prototype laboratory test (TRL 7)

Real life testing (TRL 7-8)

Pre-commercial prototype (TRL 9)

Small-scale implementation

Medium to large scale implementation

16,500 m² of SDP / 11, 000 m² of straw-insulated timber frame walls

Economic profitability of the project (ROI)

Short term (0-3years)

Middle term (4-10 years)

Long term (> 10 years)

Illustrations of the project

The 16,000 m² establishment maximises the use of local resources, both in terms of manpower (local companies and subcontractors), construction methods (wooden framework from Massif Central forests and straw insulation from Limagne), and energy supply choices. Savare, a subsidiary of Eiffage Construction specialising in the manufacture of timber structures, chose to set up a workshop in the immediate vicinity of the site in order to make the best use of local resources. This workshop is set to remain open depending on market potential, with the opportunity for several permanent jobs.

The project therefore contributes to several SDGs:

In addition, the wood frame and compressed straw insulation walls benefit from a guaranteed French traceability label. Owners and customers rightly demand better knowledge of the origins of building materials used. For this reason, since 2017, Eiffage has voluntarily committed to a process of wood traceability from the forest to the construction site, which provides the highest levels of transparency for customers. Since 2017, the Sustainable Development and Transverse Innovation Department has been working with Swiss firm Product DNA, an independent expert in supply chain traceability. Product DNA traces materials from the design phase of the project, reconstructing their entire journey based on accounting documents, and publishes labels on delivery of the project concerned. These labels provide specific information on the origin of the supplies, transformation sites, and sustainable management of the resource used, stored in a tamper-proof blockchain system.

Eiffage Génie civil Forézienne


Eiffage Energie Systèmes 


Eiffage Route

Eiffage Construction Auvergne

Eiffage’s other projects :