A research lab connecting ecology and construction

‘The state must be exemplary,’ declared French housing minister Julien Denormandie when, in February 2020, he mandated that public-sector building projects should employ at least 50 per cent timber or other bio-sourced materials by 2022. Yet, just two years earlier, recalls Louis Téqui, founder of Paris-based Atelier Téqui Architectes (ATA), his was the only practice to propose timber construction in the competition for the Centre for Research and Development in Food and Agronomy (CRDFA), located just outside Arras in north-eastern France. ‘In fact the technical consultants we hired told us that building in timber would be impossible for this kind of facility,’ he continues. ‘We were immediately able to prove them wrong, though, since we had already completed a very similar research building in timber for the National Centre for Scientific Research (CNRS) in Saint-Pierre-lès-Nemours, in 2016.’

Funded by various public bodies, including the French government and the EU, the CRDFA provides research facilities for two institutions: the National Research Institute for Agriculture, Food, and the Environment (INRAE) and the University of Artois. Both these research departments were previously located in ageing premises that were costly to renovate and it was decided to pool resources and build a joint centre, in the expectation that synergies and common projects would result. ‘We’re chemists,’ says Annie Guérin, a director at the CRDFA. ‘Our basic job is soil analysis, which we carry out for various public-sector institutions. We have about 20 staff here, while the University of Artois has 10 or so. We’re currently involved in a project with them to work out the best way to wash pesticides from vegetables.’

Half an hour’s walk from central Arras, the CRDFA is located on a busy road in a loosely developed and rather characterless urban periphery of light industrial buildings, its site a chunk of the car park that once served Arras’s now-disused cattle market. ‘In the absence of urban cues,’ says Téqui, ‘we sought to make a building that would act as a reference for future development.’ Aligned with the road, from which it is slightly set back, the two-storey building takes the form of a compact rectangle, organised around a small central patio that brings daylight into the building’s heart. While the main façade on the road is principally timber-clad, the entrance at the southern end is signalled by a concrete elevation rising slightly higher than the rest of the building, which Téqui intended as a nod to the civic belfries for which Flanders is famed. A cantilevered porch indicates the entrance, while INRAE’s logo is impressed into the concrete at the summit.

For Téqui, the use of two principal materials—prefabricated concrete panels for the entrance block, timber for the rest—avoided monotony and allowed the qualities of the wood to be highlighted through contrast. He also felt that the entrance wing, exposed to deliveries and shocks, should be harder-wearing than the rest. The combination also expresses something of the reality of the timber parts of the building, which are in fact a mixed-material construction, with in-situ-poured concrete foundations (which rise a metre or so above grade to protect the façades from rain splash), elevations in Douglas fir, columns and beams in spruce (solid, glulam, or CLT, depending on the loads to be borne), and floors in a combination of wood and concrete.

‘On top of the beams, OSB panels have been laid, to which are attached thousands of metal connectors that allow you to pour a concrete floor. After it has set, it becomes one with the wood,’ explains Téqui. ‘The advantage of this system, only fairly recently patented, is that it allows wider distances to be spanned.’

In some ways, the centre at Arras is a continuation of the research the practice carried out at the laboratories at the CNRS at Saint-Pierre-lès-Nemours, whose basic premise they have pushed much further here. At Arras, the linear plan has evolved into something much more dense—a cloister-like organisation with labs and offices lined up around the outer and inner façades so that all receive plentiful light. Where structure was only tentatively exposed inside the CNRS, far more is revealed here, including HVAC and piping, since there are no suspended ceilings. ‘The building is almost pedagogical in the way it shows how it’s put together, and we felt it would be interesting to apply that logic to the technical installations,’ says Téqui. ‘The centre is a tool in the service of science, so you see the machinery; you understand how it works. It also makes for easier maintenance.’

Frugality was also a watchword at the CRDFA, since the budget (€4.2 million) was extremely tight for such a technical building – something the choice of timber construction did nothing to alleviate. ‘In France, right now, for larger buildings at any rate, timber comes in at roughly 10 per cent more than concrete,’ explains Téqui. He attributes this to the timber industry being far less developed than the concrete sector. ‘But the client knew that when they chose our scheme,’ he continues. ‘I think we won precisely because we proposed wood, especially now the word “environment” has been added to INRAE’s remit. For decades INRA, as it then was [until 2019, when it merged with the National Research Institute for Science and Technology in the Environment and Agriculture], was encouraging all sorts of products that polluted the fields of France, so they needed to go in a greener direction.’

So how green is the CRDFA? With its compact massing and 28cm-thick façades, it certainly ticks the thermal-insulation box. As far as possible, the timber was sourced in France. All the Douglas fir comes from French forests, but they were unable to supply the structural timber, which was imported from Germany. To reduce embodied carbon, even the windows are in wood, though the frames are clad externally in aluminium to reduce maintenance. But one wing of the building is in concrete, insulation is in glass fibre, heat is supplied by a gas boiler, and cooling by a classic air conditioning system. ‘When you push things a long way with respect to one aspect,’ says Téqui about the use of timber, ‘it’s generally best to avoid doing it with the others.’

Though it stops far short of certain eco-experiments in housing, the adoption of timber construction for the CRDFA is pioneering in the French research sector, an elegant and economical response to a shifting paradigm.
Andrew Ayers is a Paris-based writer on architecture

Architect’s view

The new INRAE building has features that are both adapted to its use and exemplary from an environmental point of  view. The vertical load-bearing structure is made of wood and the floors are of both wood and concrete, which allows large spans. All these elements, as well as the wooden frame walls and the ‘travertine’ stamped concrete walls, were prefabricated before being transported and assembled on site.

The services networks are visible for easier maintenance and a better understanding of the functioning of the laboratories. The resulting lively architectural expression shows its construction without being forced or over-complicated.
Louis Téqui, founder, Atelier Téqui Architectes

Client’s view

The new Agronomic and Agrifood Research and Development Center of Grand Arras was inaugurated in February by the president of the University of Artois and the CEO of INRAE. Dedicated to agronomic and agri-food research, it aims to strengthen the international reputation of the two INRAE labs and the University of Artois. Both deal with the life cycle of phytosanitary products, from soil to food.

The new building brings together teams from the soil analysis laboratory (LAS) of the INRAE Hauts-de-France centre and the food quality and food safety research teams of the cross-border UMR BioEcoAgro from the University of Artois.

The LAS is INRAE’s national laboratory offering soil analysis services for INRAE researchers and its institutional partners: through physiochemical analysis and characterisation of soil quality. It contributes to the Hauts-de-France region’s work on soil pollutants, such as heavy metals, organic compounds, and residues of phytosanitary products.

The new building’s wooden frame and concrete entrance volume provide durability while integrating ecological materials. The project aims to respond to regional concerns relating to environmental issues including ecological transition and sustainable agriculture.
INRAE

Working detail

The building consists of a timber-frame main volume with timber cladding, which rises to a first floor. The entrance is under a cantilever on the south façade, marked by a higher volume equivalent to a second floor and seeming more massive because it is built in stamped concrete.

The building is essentially designed with a wooden structure which is itself clad in Douglas fir. The structure sits on a travertine stamped concrete base with a water-repellent coating. The wood and concrete complement each other to express firstly the structural choices, but also to bring a great durability to the work while integrating more ecological materials.

A metal profile in a deep gray colour girdles the building between ground and first floor, reinforcing the horizontal dimension.

The entrance space is extended inside by a patio, around which the building revolves. This allows natural light into the building but also offers the various users a landscaped outdoor space. It is a place of breathing and relaxation.

This arrangement around a patio makes it possible to respond to possible changes to the building and also facilitates future restructuring in the medium and long term.
Louis Téqui, founder, Atelier Téqui Architectes

Project data

Project start  February 2019 
Start on site July 2020 
Completion March 2022 
Gross internal floor area 1,821m² 
Construction cost  €4.2 million
Construction cost per m²  €2,300
Architect  Atelier Téqui Architectes
Client INRAE, Université d’Artois
Structural engineer  OTE Ingénierie
Project manager Louis Téqui
Principal designer Louis Téqui
Approved building inspector  APAVE
Contractors  Ramery Construction Bois (structural work),  Moretti Constructions (concrete work), Ramery Enveloppe (airtightness), Engie Axima (heating, ventilation and air conditioning, plumbing), Eiffage (laboratories)
CAD software used  AutoCAD, Revit
Annual CO₂ emissions 6 kgCO₂/m²
Environmental consultant Otelio
Laboratory design CITech

Sustainability data

Heating and hot water load 13 kWh/m²/yr
Total energy load 67 kWh/m²/yr
Carbon emissions (all) 6 kgCO₂/m²
Airtightness at 50Pa 1.7 m³/hr/m²
Overall thermal bridging heat transfer coefficient (Y-value) 0.097 W/m²K
Overall area-weighted U-value 0.476 W/m²K
Predicted design life 100 years