Christian Devillers: "Sustainable development at several scales"

"There can be no sustainable development in isolation", says Christian Devillers, for whom this a priori obvious statement is often difficult to put into practice due to the traditional division of labour and different types of logic used in various sectors, in which each player restricts himself to his own field or to the networks that he uses.  "For example, it is not enough to make low consumption buildings if we do not think about what type of energy we are going to use for them".   Similarly, talking about transport means going beyond the scale of a building or a district, to consider a complete built-up area.   The purpose of an urban project is to attempt to set up a relation between the different sectors and the different development and construction scales: "This is not an artist's impression or a master stroke by someone who knows, but rather a means of creating a transverse relation between logic used in different sectors to produce a space in which people want to live, rather than simply a developed space with all necessities."

More closely knit neighbourhoods

What is a region?  What is a metropolis?  In the Greater Rheims area in which Louis Kahn's former student does a great deal of planning work, almost half of the population lives in urban and rural areas rather than in the town itself.  This population is frequently forgotten or badly served and does not have much available public transport, although mobility has become a right.  "Anyone persistently unable to travel is now excluded from society ", he says.  After a century marked by a widespread increase in travel distances and the size of self-contained living areas, the objective now is to reverse the trend and give priority to proximity.  But before this can be done, proximity has to be defined.  Christian Devillers and town planner Marc Wiel share a vision of proximity at several scales:

Firstly the district, in which we find everything to satisfy all our daily needs within a 500 m radius, or the equivalent of 10 minutes on foot or on a bicycle.  A district is served by public transport to get to the place of work and to change to the next scale, the large town, which must offer services related to urban life.  For example, this second proximity scale includes stadiums or theatres, and a local railway station offering access to the final scale which is the metropolis with high speed railway lines.  It is obvious that these proximity scales correspond to mobility scales:  "Speed is discouraged in districts, while everything is done to increase speed at the intercity scale".  Although these proximity relations are theoretical, they are useful in getting an overview and knowing how to take action:  "Questions of mobility and proximity are today's biggest town planning questions".

Bercy - Charenton
Ginko - Berges du lac
Grenoble - Retail park

Towns, places of socio-economic exchanges

For the Rheims and Rennes projects, Christian Devillers obviously makes use of these concepts to design a sustainable framework, particularly by relying on existing infrastructures, nature, relief and the hydrographic characteristics.  For example, in the new ViaSilva district in Rennes, "Constructions are not organised as a function of transport infrastructures like roads and crossroads.  Rather, they are more dependent on the forest and green belts that form large landscape breaks including waterways and meadows in which water can collect and be treated before being released into the River Vilaine.  With a zero pipes objective."  These environmental ambitions resulted in Christian Devillers and the clients with whom he is working being recently awarded two prizes for projects in Grenoble and Bordeaux, including the 2009 National EcoQuartier prize for the Bonne ZAC (Concerted Activity Zone).  But the town planning architect is just as active in socio-economic topics as he is in maintaining close relations with the region.

Once again in Rennes, the program includes a precisely-targeted solution with the construction of 40,000 homes for 40,000 jobs created.  "The town of ViaSilva is an inherently sustainable place to live and work", he says about the "Cœur d'Orly" operation where the economic centre will be matched by a town centre that it does not have at the moment. "The genuine integrator, the genuine value creator, is the town and not the activity zone! ".   This study on the place of socio-economic exchanges will be naturally extended to "islands" in cities, but at a smaller scale.   Christian Devillers has been developing urban forms composed of "complex" islands with versatile mixity, ever since the major Plaine Saint-Denis urban project.  In these islands, travel mixity and social mixity cohabit with functional and morphological mixity*: "The town must be mixed.  It must include all kinds of homes, activities, and all kinds of morphology within each of the islands.  We are working strongly against this division created in the XXth century in which apartments are separated from areas of detached houses.  This did not cause a social segregation by itself, but it certainly encouraged it."


* Travel mixity: quiet traffic, roads shared at 20 kph …
Social mixity:  combination of all occupancy statuses (social purchase or rental, free purchase, free rental, etc.).
Functional mixity:  housing, activity, shops, facilities, etc.
Morphological mixity:  apartments, intermediate housing, detached houses.