siège social Notre Logis
21 October 2019

“We have to design robust buildings”

Christophe Charignon BD.PNG

Christian Charignon, Director of the Tekhnê architectural firm whose hallmark is timber construction, gives us his analysis of the environmental regulations and points out their limits. A vision without compromise of the architect’s role in reinventing the earthly habitat.


After the 2012 French thermal regulations focusing on energy performance, the next wave of environmental regulations will incorporate carbon assessment. Is that good news?

As eminent climatologist Jean Jouzel points out, it’s an extremely complex equation we have to solve. Our carbon “production” credit for limiting global warming to 2°C is diminishing at a disturbing speed. Construction and fitting-out alone account for nearly half this credit. That’s the extent of our responsibility. We can therefore but rejoice at the advent of regulations less primitive that those of 2012, given the size of the carbon issue. These new regulations will instil awareness among everybody involved in construction, but we are still only on the doorstep.
High energy performance levels of 15kWh/m²/year rely on the installation of much equipment that itself has a sizeable carbon footprint. Is it then better to accept higher energy consumption, use less equipment, and achieve a higher performing 30-year LCA? I’m worried the energy brief of the 2020 regulations puts the carbon issue out of proportion when what we need is a totally integrated approach. My last doubt concerns the much debated INIES-FDES datasheets from the Building scientific & technical centre, which introduce heavy bias into calculations, notably on timber, a material we use a lot. For several years, we at Tekhnê have been using e-LICCO, a joint software development with Cycleco. It can estimate the “grey” energy in architectural projects thanks to LCA conducted early in the design phase. And we use the ecoinvent database, whose big advantage is to allow the amendment of product characteristics via a validation committee. In this database, authenticated local timber doesn’t have the same carbon footprint as timber from Siberia. Details like these are essential for tackling ACV and for guiding choices more effectively. So far they do not feature in the thinking on the 2020 regulations.

Buildings are incorporating more and more technology. Does this trend sit well with current environmental issues?

I don’t think so. The spread of technology in buildings—smart buildings—is a huge area of vulnerability. Its makes occupants highly dependent on systems that must run correctly, while overlooking their greed for energy. To adapt to climate issues, we must forge a path to more robust, resilient buildings. To improve thermal comfort while reducing consumption and emitting less CO2, contextual design is important: first by applying bio-climatic principles, then by working on the building shell, introducing natural ventilation wherever possible, possibly having ground-coupled heat exchangers, and last by turning to bio- or geo-sourced materials. We recently delivered a gymnasium in Lyon’s 7th district made from timber and using 30cm of straw for insulation. This natural material helps offset the summer heatwave. Verdict: user comfort remains high, even during extended hot spells. In the same vein, we did the headquarters of affordable housing provider “Notre Logis” in Halouin, accredited PassivHauss and Bepos. The structure is mixed timber/concrete, the whole shell is timber with mineral wool insulation cover, fixed sunshades have been installed at the south, and geothermally-sourced heat is distributed by an active slab. During temperature spikes, the groundwater cools the structures and freshens the interior. And all the materials used are sound, with a low carbon footprint. That’s what I call a robust building, one capable of getting through the next perilous 25 years without snags, limiting intake and discharge in the environment.

Will the architect’s role in the design and execution of buildings be affected by these changes?

The profession of architect is under threat. We have been typecast in a role of space, layout, and frontage specialists. Many of today’s architects are “above ground”, not really knowing what a building site is. They must literally come down to earth, give some sense to the materials they work with. That’s the very essence of this business. Design isn’t a mere matter of running calculations in design office software; architects must master every facet of their trade, orient, propose, educate; their vocation is to integrate a multitude of dimensions: energy, carbon, user comfort, quality and functionality of spaces, execution of works, budget, and beauty! I’m an activist in the revival of this stance.

Sie¦Çge social Notre-Logis ext -® Renaud Araud - BD.PNG

« Notre logis » headquarter - ®Renaud Araud

Gymnase Alice Milliat -® Julien Lanoo - BD.PNG

Bon Lait gymnasium, Lyon 7 - ®Julien Lanoo

Thank you Christian Charignon, Director og the Tekhnê Agency for his testimonial.

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