Sustainable Solutions: We already know what to do

By Will Arnold, Head of Sustainable Materials, Useful Simple Trust

Picture yourself standing next to a machine that devours mountains. A kiln the size of an aeroplane – one that rotates, roars, vibrates, relentlessly. It’s fed with crushed rock at one end, and spits out the world’s most widely used construction material at the other: cement. It’s the precursor to concrete. The foundation of our civilisations. And when you look at the numbers clearly, it’s one of the most climatically destructive substances humanity has ever produced.

I’ve spent years writing and speaking about such materials. Our industry is totally addicted to what I think of as ‘the big five’. Concrete. Steel. Glass. Aluminium. Bricks. Look around you, and you’ll see these everywhere – forming the buildings that we call ‘home’, ‘work’, and everything in between. But while we are reliant on such buildings, the combined impact of these five materials on the planet is enormous:

• 10 per cent of all global emissions (4x the aviation industry).
• 30 per cent of all waste on Earth (second only to food waste).
• 50 per cent of all raw materials extracted from the ground (3x the volume of fossil fuels extraction).

I don’t share these to scare you (well, maybe a little). I share these because an understanding of the problem is the first step in understanding our potential to change the world for the better.

The problem is, the systems that produce these five materials are convoluted, opaque, and energy intensive. A high-end window in a British house could conceivably contain French glass made from German sand, assembled in a Polish factory, fitted into Austrian aluminium frames (using Guinean aluminium ore) and attached to Swiss stainless-steel hinges (Brazilian iron ore), before being shipped back to the United Kingdom on a boat passing through Danish and Swedish waters. Each of those steps consume energy and fossil fuels, and create emissions and waste. It’s a trail of destruction totally hidden from sight by the time our materials arrive on our building sites.

But this can all change. I don’t say that as empty rhetoric, or in anticipation of some future breakthrough. The solutions are here today. They’re real. I have samples on the bookshelf above my head as I write this.

We already have the materials we need

The truth is, decarbonising our industry is not a technical problem anymore, it’s a societal, political, economical one.

Look at concrete. We’re seeing the rise of calcined clay in the UK, a domestic, low-energy, abundant material capable of replacing one third of the cement we use in most concrete mixes today (and likely more in the future). Reclinker – the world’s first low-energy and low-carbon cement-recycling technology – is now available to buy in a blended mix, ready for use.

In steel, it’s been several years now since Hybrit produced the first real piece of iron-ore-based-steel with zero fossil fuels. No need for a mad race to try and hoard scrap: we need to get behind the ongoing work that’s building million-tonne-capacity green steel plants in Sweden, China, Namibia and beyond. 

Glass recycling in the UK is reaching new heights with companies like Saint Gobain paying to collect glass from building sites. Aluminium-making just needs more renewable electricity and hydrogen. And bricks made from crushed waste, such as Earth4earth and Kenoteq can be produced – today – with very low levels of heat. Supplement all this with the continued rise in timber, biochar, mycelium, stone, bamboo, unfired earth and more, and you can picture what we CAN build from today. The challenge is not invention, it’s adoption.

We already know how to use less

But in the same way that our future materials are not yet mainstream, neither is precise, refined, circular design. Our industry has a weight problem and a disposable building problem. But again, both are solvable at once.

Society is vocal about the need to avoid throwaway packaging and fast fashion. Our job is to convince them to care as much about buildings as they care about keep-cups. But if we do this, the list of benefits is long and rich. When the Kendeda Building was designed and built for the Georgia Institute of Technology in the USA, it became one of the few dozen buildings to achieve full certification under the Living Building Challenge. Novel concrete mixtures were trialled by injecting carbon dioxide into the pour, and a passionate commitment to material efficiency resulted in ultra-lightweight columns reminiscent of masts on a yacht. But it was the team’s obsession with reuse that really stood out, with 28 stories of reuse, including the saving of 7km of discarded timber from film sets, nailed together into new floor panels, and all by a gang of workers provided Georgia Works!, a non-profit that brings unhoused people back into work. Near-zero emissions, AND continued sequestration of biogenic carbon, AND zero waste, AND creation of green jobs for those that needed it the most.

None of this need be a compromise. These are “and, and, and” solutions.

We already have our compass

Our final step must be to combine our circular and efficient use of new materials with a desire to do good things with them. In Future Build, I consider buildings as value-exchangers, delivering “societal return on ecological investment” (or in short: “value for carbon”).

Regenerative design explicitly asks us to consider how to replace harm with healing, and we can only do this if we understand how our constructions do good and bad, both on-site and at the places we get our materials.

Asking these questions, alongside a ‘north star’ such as Doughnut Economics, helps us identify our project’s biggest opportunity for benefit, and maximise our response to that opportunity. If our challenge isn’t technical but is cultural, commercial and collective, then we need to bring others with us – this means giving people more bang for their buck. Our industry is already stuffed full of examples of this happening. Our job is to amplify those examples, and make them the norm.