A Rubbish Museum

Yesterday, The Guardian’s architecture critic Oliver Wainwright reviewed the new extension to Ghent’s Design Museum, some of which its architects designed to use the remains of buildings demolished nearby.¹ The €20m museum contains 82,000 bricks, each made of 63% construction waste collected within eight kilometres of the site.² Pulverised and pressed with hydrated lime, they save two-thirds of the embodied carbon of conventional fired-clay bricks, and the lime keeps absorbing CO₂ as it cures.

»The easiest way of redeploying a material in an industrial economy starts with destroying the object«

Andy Groarke of London-based architects Carmody Groarke, one of the practices behind the design, is cited in the article as saying »There’s nothing new about reuse. We’ve just forgotten how to do it.« He’s half right. We didn’t forget how to reuse materials the way we forgot about, say, phone numbers. Of course nobody memorises phone numbers anymore, not because the numbers got harder to remember, but because mobile phones made remembering them redundant. Reuse went a similar way. It didn’t become difficult; it stopped paying its way.

In Ghent, the nearby Saint Bavo’s Cathedral shows what reuse paying its way looked like. Some of this Gothic building is made from the limestone of a tenth-century basilica that stood on the same site; renovation work has even uncovered walls made partly of human bones. That’s reuse in its plainest form: stone remains stone and goes back into new walls. Reuse is arguably the hottest trend in architecture right now, but back then it was probably less an environmental gesture than a sensible way to build when new stone cost more than old. What changed was the price of labour relative to materials. Factories made new bricks ever cheaper, while taking a wall apart by hand stayed as slow as ever, and wages rose with the rest of the economy. The economists William Baumol and William Bowen described this effect in the 1960s.³

That’s not the kind of reuse that was applied to the bricks in Ghent. Nobody lifted old bricks into a new wall. Instead, the old material was pulverised and ceased to exist as a brick. That’s recycling rather than reuse, and it’s no accident that this is the version we can manage, because crushing avoids exactly the labour that made reuse uneconomic. The easiest way of redeploying a material in an industrial economy starts with destroying the object.

In Rubbish Theory, the anthropologist Michael Thompson proposed that objects move between three categories. The value of transient objects declines, the value of durable objects holds or grows, and rubbish, which has no recognised value, doesn’t cost anybody anything, and is the only category from which objects can be rescued.⁴ A brick in a skip hasn’t changed physically, but its status has changed. The economic and cultural explanations are one loop: when disposal is cheap, used things become rubbish, and once they are rubbish nobody keeps track of what it costs to throw them away. Change the price and the status can change. Change the status and the price follows.

The philosopher Hannah Arendt saw what’s at stake here. For her, the things we build give life a stable world to exist in. Those things can do that because they outlast us. A society that devours and discards what it builds, she said, has become a »waste economy«.⁵ Seen that way, the museum is odd. It rescues the rubble of buildings that were never meant to last.

But the market didn’t fix this on its own. For a builder, dumping rubble is cheap. The real cost falls on everyone else. Economist Arthur Pigou pointed out in 1920 that when a cost lands on others, too much of the costly thing gets done.⁶ So Ghent’s recycled bricks needed the taxpayers’ money for the research, testing, and certification that the market wouldn’t pay for.

It’s not a complete answer, and the architects say so. Sian Ricketts, Carmody Groarke’s sustainability lead, calls the building »a sort of 82,000-brick proof of concept«. It doesn’t solve the climate crisis, Ricketts says, but it shows that something different can be done »with the right collaborators and the right clients«.

The Swiss architect Walter Stahel and socio-economist Geneviève Reday-Mulvey argued in the 1970s that reuse, repair and remanufacture swap labour for energy and materials.⁷ The lever, then, is the relative price of the two. Ghent’s museum is an attempt to pull that lever, and by doing that change the status of rubbish. We can’t simply remember our way back. Reuse will start paying its way again when it costs less to put an old brick in a new wall than in a skip.

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