The current debate over the proposed 'eco-towns' that has had communities holding demonstrations, developers withdrawing schemes, planners and advisers worrying about transport and the usual suspects predicting the concreting of our verdant hills, focuses the mind on what we really mean by 'eco'. The isite blog has touched on this already, focusing on the rather weak green credentials of some of the probable eco-town projects, and I hear Rob has cogently summarised the issue for buildings as 'carbon, cost, comfort': "What's the point of creating a technically perfect low carbon building if the occupier doesn't like it or won't use it the way you want to?" (via Phil). At the larger scale: what's the point of building a zero-carbon housing estate town in the wrong place for transport, for local communities, for the bigger picture? Sustainability is not simply about carbon: it is about sustaining communities functionally and psychologically; reinforcing or creating a sense of place that engenders pride, that will encourage all generations to live there for the long term, as well as providing the buildings and services that they need to do so, and limiting our impact on the climate and environment.

Most local communities want affordable housing for their children, and lower carbon emissions; and it is easy to imagine a way of consulting over the location for new 'eco' development that would be vastly less contentious than getting developers to submit bids to central government. It is damaging to genuine efforts towards a lower carbon footprint that unsustainable projects such as some of the 'eco-town' sites are badged with the 'eco' label. Cynicism about the impact of low-carbon policies on everyday life is already increasing, and if popular suspicion reads every government 'green' initiative as a covert way of doing something unpopular, support for measures that might genuinely do good may well wither away.

The same goes for products that are dubiously badged 'eco'. Like the rest of the world, I was at Ecobuild for a few hours this week and left dispirited at the crude rebranding of plastic and aluminium windows, timber products shipped across the Atlantic, and unrecyclable insulation as 'green'. Prize for the most absurd 'green' product probably goes to the "basalt fibre reinforced polymer" wall-tie which is supposedly better than the steel one because it minimises thermal conductivity; this may never take off in the building industry but some of the more serious products are equally contradictory.

One problem is that the word 'sustainable' is so fuzzy that terms such as 'eco' and 'zero-carbon' have been seized upon as substitutes, although they tend to narrow the debate to something purely technical. There is a need to reclaim the debate from the point-scoring of codes and percentages, however difficult it is to do so in language that is clear and unambiguous. Otherwise there is no way that our carbon emissions are really going to reduce - we need to address the system, not just the symptoms.