It's seldom noted that buildings are one of the most important items on the climate agenda. In 1990, the construction and use of residential, commercial and institutional buildings was responsible for about one-third of global energy use and its associated carbon emissions. In developed nations, buildings account for 40 per cent of total energy consumption and 60 per cent of electricity use. Some projections of energy use in the buildings sector show a doubling between 1990 and 2020; aggressive adoption of energy-efficient technologies could reduce this growth to just 36 per cent.

Much of the focus on making buildings greener has been on energy-efficiency: better insulation, low-energy lighting and so forth. That makes sense, although it is disheartening to see traditional low-energy methods such as wind-catchers and ice cooling in the Middle East being replaced by energy-hungry air-conditioning.

But it is sobering to discover the costs of construction alone in terms of energy and materials. As John Fernández of the Massachusetts Institute of Technology points out in a recent review (Science 315, 1807; 2007), 70 per cent by weight of materials use in developed nations is accounted for by the built environment, and 60 per cent of non-industrial waste comes from construction and demolition of buildings. And get this: 8 per cent of global CO2 emissions come from concrete production alone.

So there are lots of good reasons to use new materials in buildings: potentially this could cut their energy consumption, reduce waste and increase their lifetimes. Fernández lists many of the attractive solutions that now exist, but he points out that historically materials innovation has been slow in building technology. It took six decades for commercialized PVC to become a construction material, and adoption of the glass-substitute ethylene tetrafluoroethylene has also been slow. Neither of these is perhaps the 'greenest' of materials, but this reticence in the building trade is general.

Why is that? Sometimes advanced materials are just not economical. 'Active' glazing, with electro-, photo- and thermochromic properties, offers low-energy solutions but at often prohibitive cost. The same remains true for organic light-emitting diodes. But one of the main obstacles is that designers and engineers fear the legal liability they face from using materials of unknown lifetime and performance. And neither the client nor the builder wants to pay for testing of unproven materials.

But where there are substantial potential benefits from the introduction of new materials, this seems a most unsatisfactory situation. Is it time for the construction industry to follow the lead of some energy companies in supporting blue-sky innovations that might help the environment?

Of course, sound materials use doesn't need to be high-tech. Large civic buildings are typically expected to last for 120–150 years today, but medieval churches made from stone, wood, metal and glass are still functional centuries later. True, they often need extensive restoration and maintenance; but they show that there is no reason, technical or aesthetic, why we should not sometimes aim to build for eternity.