Eco-cities have appeared for some time as the promise to bring sustainability to cities. They are presented as integrated projects to construct Utopian spaces for the development of a new inhabitable areas that fully comply with the requirements of reduced CO2 emissions (zero emissions), and less waste (zero waste), etc. They embody an optimistic vision (an urban structure can be built which is capable of sustaining itself and maintaining a systematic balance in its ecological operations) but also a pessimistic vision (sustainability is impossible to achieve in an already constructed city and it is not worth making an effort to solve the unsustainable current urban model). Some internationally well known cases can be found, such as Masdar or Dongtan (the latter city, suspected of only being propaganda), presented as mega-projects, and others on a smaller scale in urban regeneration processes, such as the well known case of Hammarby Sjöstad (eco-neighbourhoods), and in all cases they are built on a sustainable ideal. The  Manual for the eco-cities project in Europe, result of the Eco-city project, is a good guide to understand how this type of action is interpreted, although this case above all refers to a neighbourhood scale.

In the newly published book by Earthscan, Building for a climate change. The Challenge for Construction, Planning and Energy, I have found a  very critical chapter with the current boom in eco-cities (or eco-towns) as an integrated urban development, based on sustainability criteria. The chapter (Eco-towns: opportunity or oxymoron) focuses on justifying how the British authorities have systematically rejected this kind of projects. In an important debate held almost two years ago (limited to the British case, but of general interest), Simon Jenkins, a journalist specialized in urban and architectural subjects at The Guardian, stated clearly where the problem lies and closed a comprehensive article (Eco-towns are the greatest try-on in the history of property speculation) with a particularly scathing comment: "Building new houses emits 4.5 times more carbon than rehabilitating old ones, new eco-towns are a big failure". Dermot Finch, director of the Centre for Cities wrote similar arguments some days later in Eco-towns are not the answer to climate change or housing needs and even Richard Rogers himself replied in the same newspaper, supporting these critical approaches and suggesting that the authorities should give up the idea of supporting the construction of a series of eco-cities in the country. Despite this controversy, finally at the end of 2009 the British government supported the construction of four eco-towns, with the opposition, among others, of the Campaign to Protect Rural England.

Ethel Baraona recently wrote a very accurate article on the problems of the concept of attempted sustainable architecture that forgets to look at the urban metabolism as a whole, where the central problem is the energy model for cities. In the British debate an extra element is added, the possibility of favouring speculative real estate processes on non-built up land, an element which is not significant in our case, because, unfortunately, we have not needed the excuse of sustainability to see these speculative dynamics. More interesting is, however, to notice how they can become an element of distraction to divert attention from what is really necessary.

And this debate is urgent; firstly, because the cranes have stopped and the winds of change of the productive model speaks of sustainability and the temptation may be to aspire to create new activity in the construction sector promoting developments in the form of ex-novo eco-cities. And, secondly, because a decided commitment to the renewal of private housing, industrial areas and equipment and public buildings is absolutely urgent.

These eco-cities (as in the case of Sarriguren, so well known in Spain) have had a certain demonstrative value, as pilot experiences for the potential application of new technological solutions to heating systems, insulation, and energy consumption in buildings, but are not acceptable as a solution. In a country in which thousands of homes are empty, no new homes should be built, at least if we consider the objective rationale of social housing, and any urban development that is justified by its sustainable advantages will be false or, at best, a well-meaning mistake.

Only by solving the problem of growing residential energy consumption will advances be possible in the mitigation of climate change, and already constructed housing will require an effort in the application of new materials and new solutions in the renovation of this housing, and only by intervening in the physical design of existing urban space will we be able to get cities and urban lifestyles to approach, although only slightly, a more sustainable future. With the construction industry practically paralysed, both central government and autonomous government plans for housing and urban development have to focus on the renovation of the urban fabric.

Photo taken in Lincoln, Nebraska (Haymarket District) and downloaded from the project Power to the poster.