What’s stopping us from reusing materials (two years later)?

Just over two years ago I wrote my first column for BD online about the reuse of materials, in particular the reuse of steel. At that point steel reuse still seemed like something we could be doing but weren’t, and while we’ve been reusing steelwork in-situ within buildings for years, deconstructing steelwork to reuse in other buildings seemed liked an ambitious concept.

Fast forward two years and the Steel Construction Institute (SCI) have published two guidance documents for steel reuse, several companies have made stock matching tools and there are completed buildings evidencing how steel reuse can be done. We have much more defined processes for certification, we know how to catalogue and remove steelwork from existing buildings, and we know what testing is required.

In the coming years it’s likely that steel reuse will be a planning condition for re-development projects in London. We’ve made huge progress, and while this is mostly happening in London at the moment, it’s worth reminding ourselves how far we’ve come.

So how do we keep this momentum? And what do we need to do next?

So far, we’ve developed a process for steel reuse that fits with our pre-existing methods for both demolition and design. Regardless of whether steel has bolted or welded connections, we cut the steel to remove it.

This is partly to avoid issues removing bolts, but also because it’s a demolition process that we’re used to using. When it comes to design, we choose the sections that we want and then try to find them, rather than looking at what’s available and adjusting our designs to suit.

Could we make material reuse the norm rather than the exception?

We’ve made a great first step, but if we want to maximise material reuse then we now need to consider whether we should completely overhaul the way we’re working. It’s a much more difficult change - demolition stages in programmes need to be much longer and design processes almost need to be reversed.

Currently we optimise to find the best steel size for the grid we have, and we’d instead need to adjust the grid for the steel that’s available. It’s a process that would require a lot more coordination between the architect and the engineer but it’s certainly possible.

The other issue is that there’s still no incentive for clients to provide materials to the market for reuse. If materials can’t be reused within the same site then any carbon benefit effectively goes to the receiving building, and with longer demolition periods to allow for deconstruction rather than demolition, only the most sustainably minded clients would take the hit to benefit another site.

Regulation of embodied carbon would help; if there was a requirement to pay to offset embodied carbon then steel for reuse could have a “carbon credit” value and donating steel for reuse to the market might benefit the donor building as well as the receiving building.

But perhaps the most important lesson that we need to learn is ensuring that the drawings and specifications we’re producing now allow for future material reuse. We rarely produce accurate “as built” drawings, let alone deconstruction drawings.

We don’t mark steelwork so that we can find the steel test certificate for it in the future. We don’t produce an accurate record of components in the building so that we know what’s there. If we’re going to enable future material reuse then it’s a really simple change that we could make now for every project.

We’ve come a long way, and as an industry that’s definitely something to be proud of. We’ve proved to ourselves that we can and will make changes that significantly reduce our carbon, even when the challenges are difficult to overcome. But now let’s see how far we can go.

Can we change the way we’re working to maximise steel reuse? Could we implement material reuse on every project? Could we make material reuse the norm rather than the exception?

>> Also read: What’s stopping us from reusing materials?