Architecture, or at least construction, is one of the ugliest, thorniest problems of the entire climate crisis. It depends upon who you ask, and one can certainly find a bewilderingly inconsistent array of statistics, but the construction, running, and maintenance of buildings contributes something around half of all global carbon emissions. Producing cement and steel, the two most important materials in global construction, lets off huge amounts of CO2, while the heating, cooling, and lighting of buildings uses a dominant proportion of all the electricity generated across the world. What’s more, the life cycle of buildings adds another dimension to the profligacy. Demolishing buildings for replacement destroys construction materials, losing the ‘embodied carbon’ within them, compounding the negative effects of the fresh materials being extracted and formed into new real estate.

Faced with these facts, the industry finds itself in several agonising quandaries. New buildings are generally built with expected lifespans of way less than a century, but a huge proportion of buildings are old, energy inefficient, and expected to last way off into the future. Should new construction be more ephemeral, more recyclable, or should it be more long-lasting, functionally abstract, and capable of accommodating unforeseeable future needs? Some demand that there should be no new construction whatsoever until the CO2 problem is more in hand, but such a thing seems politically impossible given capitalism’s intrinsic need for growth.

A less fundamental version of this argument is seeing architecture focus far more closely on questions of refurbishment and reuse. Awards for adaptive projects are proliferating, while in architecture schools, studios are increasingly focusing on projects for transforming existing buildings — exploring principles for creative reuse, and to a certain extent subverting the classic image of the architect as creator of tabula rasa personal statements.

This is all a far cry from more heroic periods in construction, such as the generally social democratic building programmes of the post-war era. Architect John Allan, in his new book Revaluing Modern Architecture, recalls being a student in the 1960s, and being told that ‘We would be the generation of architects required to build a new city the size of Leeds each year, every year until the end of the century’. Instead, Allan built a career as one of the leading experts in the restoration of modernist architecture, an oxymoronic position that he gives much contemplation to. For an aesthetic based upon industrial novelty and underpinned by the rhetoric of functionalism, there is something intrinsically strange about the transformation of such buildings into heritage.

Not only is the idea that modernist architecture is worth saving controversial — especially among Tories — there are huge numbers of middling buildings from the late-twentieth century that aren’t really very good or particularly useful by this point, but really shouldn’t be torn down. Here, questions of climate change, cultural taste, legislation, politics, land value, and real estate, all smash together in a confusing mess of conflicting demands. Architects are in a good place to engage with these, being the only construction professionals with a wide enough perspective to do so, but it does raise the question of what can be expected from a culture of building when refurbishment is the dominant process.

‘Ultimately, reuse asks humanity to build fewer new buildings,’ stresses Ruth Lang, editor of Building for Change, a glossy new collection of high-quality refurbishments. If this is true, and the architecture of this century is about transformation, what might it look like, and what might it mean? One answer seems to be a sort of ‘haunted house’ mode, where the traces of previous use become aesthetic material to be contrasted with the new, which can result in virtuosic architecture but can easily fall into derelicte chic, and it’s hard to imagine it being popular with big corporate institutions, given the melancholy associations of ruination.

More promising approaches see existing buildings essentially as stores of carbon, with no attempt to carry the aesthetic through to the new use — we’ve written about this approach here in Tribune, when it gets used as part of a strategy to save the houses of working-class people from demolition. Here is a modernism of sorts, light, efficient, technological, and scientific, and a certain nostalgia for high-technology modernism can indeed be seen in a lot of new architecture from mainland Europe in recent years.

If we still take architecture to be a key cultural form, which perhaps in the internet age we don’t have much reason to, there’s something definitely sad about these challenges, as on the one hand the ambitious and optimistic output of the last century gradually becomes cherished, sterile heritage, and on the other hand the search for contemporary styles of building increasingly looks to live within and around the shells of the past. Is it possible to imagine living well in such pessimistic urbanism?