"Frugal", "resilient", "sustainable", "ecological"... There is no shortage of adjectives when it comes to approaching architecture through the prism of ecology. And the stakes are high.
According to UN estimates, emissions from the building construction sector represent 38% of all energy-related CO2 emissions. Yet solutions are at hand to create a greener future for architecture. This is a vast undertaking that covers the entire sector, from the materials used to the surfaces exploited, to the location of buildings.
On the occasion of European Sustainable Development Week, Christine Leconte, president of the French National Council of Architects, provides an overview of current challenges and new practices in the sector.
How would you define the principle of sustainable architecture?
If I had to summarise the concept in one sentence, I would say that it's architecture that does better with less. Our profession must reinvent itself, adapting to the context of global warming and extreme temperatures. At the same time, we need to rethink our work in a way that mitigates the causes of this crisis. In other words, create buildings adapted to today's needs in terms of comfort while reducing the ecological footprint of these constructions, for example by using fewer raw materials.
The definition of ecological architecture also varies according to the territory. For example, a building built in concrete or metal in the middle of the city can be considered more ecological than a house built entirely with more ecological materials, but whose location requires daily car travel for those who live there.
What about construction waste?
This is indeed a real problem. There's a lot of demolishing involved, which creates large quantities of waste. We even throw away doors! However, it is often possible to reuse the residues of materials from construction sites. I'm thinking, for example, of the earth extracted during the construction of the Grand Paris Express (transit lines), which will be transformed into building bricks thanks to the Cycle Terre project in Seine-Saint-Denis.
Existing buildings should be seen as a kind of raw material. They are viable ecologically, but also because they are part of history. The idea of renovating or even transforming them has therefore become vital. And the new materials are suited to this. The range of possibilities is very wide, both in the old and in the new.
Which materials should be prioritised?
Renewable materials, i.e., those that can be recycled. For example, hemp can be used as insulation, but also as a coating or as a construction panel. Then come what's referred to as "local materials". For example in France, using insulating materials that are produced in France and not in China. Hemp, straw and wood fibres, which are cultivated in our country, can be used to create effective insulation. This is what I call, in an analogy with food production, "short circuit architecture". And we shouldn't forget about earth and stone which have a capacity for thermal inertia and which enable heat to be captured (and thus avoid the use of air conditioning).
Are you seeing a paradigm shift with architects who are new to the profession?
Absolutely! Most young architects are aware of these issues and committed to the environmental cause. They are learning about wood, hemp and straw construction, etc. And we're not talking about the story of the three little pigs, but solid, comfortable and durable constructions. The young generation has completely understood this. They encourage us to question ourselves... and that's good!
How do you defend these views within the National Council of the Order of Architects?
First of all, by doing a lot of educational work with clients, but also with members of parliament, our colleagues, and so on. The aim is to demonstrate how we can achieve this, with figures and concrete examples to show how to open up the field of possibilities.
The architecture of the 21st century is in the process of being reinvented. This is even more true since the advent of the pandemic, because we are confronted with a stronger demand for quality habitats to live in, with good insulation, a balcony or a garden, etc. It is very important that architects work hand-in-hand with the inhabitants to come up with solutions together.
The "Grand Parc" project by the Lacaton and Vassal agencies in Bordeaux, initiated by Frederic Druot and Christophe Hutin, is a perfect example. These two architects have installed winter gardens to ensure the thermal insulation of social housing, while at the same time offering more living space to tenants.
In my opinion, this is the challenge of the architecture of the future: to reuse the existing properties by using the least amount of materials possible, while improving inhabitants' quality of life. – AFP Relaxnews