Edito n°41 : How do we build ecologically in the 21st century?

What role can the architect play to promote ecological building in a century destined for unprecedented climatic changes in man’s history? The question needs to be addressed on three different levels.

Building and design
How do we economize on final energy and primary energy?  We often notice discrepancies between the provisional assessments for buildings in the planning stage and those measured once they are in use. How can we make allowance for user behaviour? Are comfortable summer conditions threatened by energy-saving measures? Does the containment of premises contribute to deteriorating internal health conditions?

Regarding grey energy and ecological materials, how do we control the grey energy vested in the building? To what extent can we choose local materials, at the risk of rapidly making them extinct? Is the use of local materials condemned to only cover a marginal share of the building market? Is actively campaigning for the widespread use of local materials doomed to failure?

Concerning renewable energies, since solar energy is diffuse, large surface areas are needed to produce quantities of energy that are significant in the balance of total energy output. Where do we find such areas? Primarily in areas already occupied by urban development, such as car parks, supermarket roofs, etc. As for rural areas, it is infuriating to set aside arable land for the purpose of producing photovoltaic electricity on the pretext that such plots of land are no longer farmed! As for wood-burning fuel, production must not compete with the “building timber” sector. It must remain the product of waste recycling. Yet aren’t efficient wood-burning stoves and boilers harmful to our health, unless they come with filters that are expensive to install and service?  Besides the fact that it might impact the market for wood fuel, does the proliferation of wood-burning stoves represent as great a danger for the population as diesel engines or asbestos?
The problem, as far as the occupants’ health is concerned, is not so much the accurate inventory of the possible causes of air pollution inside, as the fact that these issues are not even raised when designing our building environment. How can we interest owners and project managers in health issues without entering into conflict with energy requirements?

The city
The urban issue can be seen in the mobility induced by urban sprawl. There are two hurdles in the fight against urban sprawl. One is the “Zahavi law”, which holds that faster means of public or private commuting encourage people to move further away from the workplace. The other concerns the conflict with “Urban Warmth Area” factors. Higher population density needs to be handled with caution, and in parallel we need to develop the green city and resolve the dilemma of the sparsely populated green city versus the populated city with virtually no green areas. The major issue is basically that of the city’s “carbon footprint” and how to reduce it. Shouldn’t the city become “bio-productive”, which would drastically change the way it is designed? Aren’t the garden-cities of the past¹ and the shared gardens of the present² the precursors of such a city, which would be capable of being partly self-sufficient by recyling part of its waste?

The world
Concerning world demographics, as Hervé Domenach and Michel Picouet³ point out, the environmental impact (I) is the result of population size (P) by per capita consumption of goods (A) and by technology (T). Another way of expressing this equation explains even better the factors we need to influence: Deterioration=Population x Production/Population x Pollution/Production. Any progress made in Production/Population ratios (by the population pursuing more sober policies) and Pollution/Production ratios (by improving the environmental efficiency of production processes, including in the residential and tertiary sector) will ultimately be offset by the population factor, which continues to grow.

Conclusion
The problem we face is global. It is hard to bring about change on a global scale. You only have to look at the failure of regulatory efforts at world summits due to the diverging interests of rich countries and the others, with very different demographic trends and economic levels, faced with public opinions and governments obsessed with indicators like GDP, for whom growth is the remedy for all ills.

Given the enormity of these challenges, what can the ideas and actions of a few architects achieve? Are they doomed to only act at local level? We undoubtedly need to prepare architects to work on adapting our buildings to the inevitable global warming forecast for the decades ahead, since it seems that CO2 emissions to date are already sufficient to alter the climate with no possibility of turning back time. What we do know about these forecasts is that the warming process will be greater in cold (polar) areas, in winter more than in summer (although we will still have very cold spells) and at night more than in the day. Here are some pointers for reflecting on how developed countries in temperate climates can build in the 21st century, particularly in the Mediterranean area, to make inhabitants’ lives as pleasant as possible, despite the socio-economic consequences that climate change will inevitably cause.

1. Jean-François & Nicolas Champeaux, Les cités-jardins, un modèle pour demain, Sang de la Terre, 2007.
2. Laurence Baudelet, Frédérique Basset, Alice Le Roy, Jardins partagés, utopie, écologie, conseils pratiques, Terre vivante, 2008.
3. In the booklet “Population et Environnement, PUF Que sais-je? 2000”; where they quote an article by B. Commoner entitled “Rapid Population Growth and Environmental Stress” published in 1988.