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Documentation > Publications > Articles > Renovating ancient housing, a widely unknown action possibility against climate change (march 2004)

Renovating ancient housing, a widely unknown action possibility against climate change

Articled published in the French newspaper "Les Echos" dated march 30, 2004

website of the author : - contact the co-author :


NB1 : This article was cosigned by Olivier Sidler, head of Enertech, and your humble servant.

NB2 : the original article was in French. Below is a translation by your humble servant.

NB3 : the text below as well as the title - correspond to what we sent to the paper. The title of what was effectively published was chosen by the paper, as usual....


Few people know that buildings, in France, absorb about 40% of the energy consumption of the country, ahead of transportation that amounts to 30%, and industry 25% : it's been only a couple years since cars and trucks emitted more than domestic and office boilers.

Few of our fellow citizens know that our government organized, during last spring, a national debate on energies, alas remained pretty confidential though at present times, without abundant and cheap energy, nothing that makes our daily life can be sustained. Given the double menace of fossil fuels depletion and climate change, the majority of the participants agreed on the imperious necessity to combine as soon as possible a decrease of the energy consumption with a still joyous life. Unfortunately, the draft bill on long term orientations for the energy policy that has been prepared reflects only very partially, in its present version, the change for a totally different strategy wished by a majority of informed individuals.

Indeed, all those that analyzed the climate change problem know it : in order to reverse an evolution that might well lead to a massive mortality before the end of the century, we need to divide as soon as possible the world CO2 emissions by two, which translates, for a country like France, into a division by four of the present emissions. In the course of an ambitous speech given last march, the Prime Minister proposed that France adopted the objective of dividing its present emissions by four by 2050, which means, incidentally, that we must have cut by half, by 2030, our present consumption of natural gas, oil and coal.

It happens that one of the places where this division will be the easiest to achieve is in buildings, and more particularly in ancient housing. Let's be clear : given the comparative easyness to achieve such a division by four in buildings, not initiating the corresponding action would be very bad news regarding the possibility to voluntarily take up the challenge of climate change. And, of course, if we do not solve voluntarily the problem, involuntary regulations, generally far more painful, will do it for us, probably much before the end of the century.

The authors of the present article thus consider that it is indispensable to include in the draft bill a very ambitous initiative aiming at renovating all ancient housing (residential and offices), the possible results at stake, widely unknown, being considerable.

All buildings completed before 1975 are considered ancient, due to the fact that there was no regulation regarding building insulation at the time ; about 17 million homes comply with that definition. It would be perfectly feasible, over 40 or 50 years, to divide by 4 the direct emissions of these buildings (heating and sanitary hot water), by combining an increased insulation and a higher calling on renewable energies (basically thermal solar, wood and geothermal). All technical elements are already fit, and a small number of completed operations can even be found in our country !

This sole renovation of ancient buildings would allow to save more than 10% of the energy consumption in France, and would generate a decrase of about the same magnitude of the greenhouse gases emissions. There are very few single measures that bear such a potential : 10% of the greenhouse gases emissions of our country, it's half of the emissions of the whole industrial sector, or even half the emissions of the whole car fleet !

Renovating about 20 million homes in 50 years means to complete about 400.000 operations per year. Such a pace would definitely raise a number of practical problems, but none of which, when taking a close look, would be more arduous to solve than those we are accustomed to find solutions to when it is the increase of the energy consumption that we wish to encourage. For example, a law could oblige any buyer of an ancient house or flat to correctly insulate it just after the purchase, both against the winter colds, and against the high summer temperatures that climatologists consider will increase in the future. Doing so would not only allow to save energy in the winter, but would also be a preventive solution to future heat waves, the price of inaction being that the use of air-con will soar, and with it the summer demand for electricity. If the latter is satisfied with gas fired power plants, it will go with a strong increase of the greenhouse gases emissions, and then we will have lost all along the line !

Such "heavy" insulation works are pretty fast to complete - not taking much longer than the traditional painting - when the home is empty, which is generally the case after a sale. These works might be financed by loans with preferential interest rates (the difference would be paid with federal money) offered by the bank along with the "classical" mortage. On the long run, the paying back would amount to less than the price of the saved energy. The cost for the federal budget would be around 1 billion euros : a lot of money in absolute figures, but peanuts given what is at stake, not to mention that such a plan would generate savings on public money otherwise (through the increase of the various incomes linked to the jobs created, for example).

Most certainly all ancient homes are not sold over a 50 year time span, and most certainly tenants should be considered through another plan, that we cannot discuss here because of a lack of space, but concentrating on the existing 450.000 yearly sales of ancient homes would already provide with a considerable flow of which a good profit could be made.

And at last an ambitious plan of this kind would allow the creation of about 100.000 jobs in the construction sector, lasting at least for 40 years, and would also allow the country to develop some know-how that would certainly benefit our external trade afterwards. France would also intiate an ambitious operation that all its european neighbors could not resist following afterwards, and that would materialize the first action with the good magnitude of rich countries against climate change. When our country is close to having a 10% unemployment rate, that each year that passes by without action means a darker climatic future for our kids, can we refuse any longer such an initiative, that allows to combine economic benefits, social benefits, and a significant decrease of the greenhouse gases emissions of the country ?


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