The standardisation offered by construction platforms (a type of modern method of construction ) is arguably the missing piece of the jigsaw. New business models made possible by construction platforms, such as Seismic, can make reuse of steel components more common and more likely than it already is.

What are the barriers to more widespread reuse of steel building components?

Current industry figures show the likelihood of steel components being recycled is in excess of 90%, while the likelihood of them being reused is in the region of 4% to 7% (depending on the type of component).

Steel is infinitely recyclable. Scrap steel therefore has inherent value, so it’s no surprise that both the likelihood of recycling, and actual rates of recycling, are so high. However, recycling is a process that uses energy and emits carbon. It is, of course, preferable to material being sent to landfill, but there are better options than recycling when it comes to long-term sustainability.

From a circular economy perspective, reusing components is the ultimate goal. Steel is infinitely recyclable, but it is also inherently durable. A service life of 200 years is achievable. If components can be reused across multiple buildings to achieve a useful life of two centuries, that saves a lot of resources and carbon emissions associated with new and recycled steel production.

At present, however, the way buildings are designed and constructed typically makes recycling a more attractive option than reuse.

Under current reuse practices, there is little issue with designing a building that can be disassembled and rebuilt in a different place. How often, though, is a specific building design with specific components required in exactly the same configuration? There are examples of such buildings, but they are usually temporary and not a template for the construction industry as a whole.

Components used in one building type and design are unlikely to be the perfect length, grade and strength for another building use. The connections aren’t quite right, and holes are not in the ideal place.

That’s why, currently, steel sections recovered for reuse tend to have the connections cut off the ends, leaving shorter sections. The marketplace for reusable components is therefore limited, which leads to the 5% likelihood figure.

How can a marketplace be created that offers a wider variety of reusable steel components? How can a building be disassembled and its components used to construct something new?
 

Does modular construction increase component reuse potential?

As modern methods of construction (MMC), modular construction systems might be expected to help increase the likelihood of reuse. However, the lack of standardisation between different solutions actually restricts reuse.

Components produced by different manufacturers are slightly different, so systems are not compatible. This is inefficient, and increases risk on projects should a modular manufacturer go out of business.

Construction platforms reduce this risk by introducing standardisation, which allows different manufacturers to produce compatible components for a single ‘platform’. This approach is exemplified by the Seismic II project, where two different systems were developed for the Seismic platform . A demonstrator building  was completed to show the benefits of the platform.

Part of the thinking behind Seismic II was to make it possible for almost any component – structural sections, fully-finished cassettes, or the entire building – to be reused. The aim became to show that Seismic, and construction platforms generally, could open up new business models for reuse of components and modules, thanks to standardisation.
 

How much more reuse of steel components is possible with construction platforms?

To help understand the potential benefits of Seismic II’s standardised structural frame, the Seismic consortium commissioned an end-of-life report. Circular economy specialists reviewed existing information on steel reuse, interviewed the MMC manufacturers involved with Seismic II, and surveyed steel frame manufacturers in the wider industry.

The report identifies that modular frame manufacturers already have their own refurbishment/reuse businesses that recover steel components when given the opportunity to do so. A viable marketplace therefore exists, and the report identifies other drivers that are increasing activity within that marketplace.

Overall, the report identifies the likelihood of reuse for Seismic’s steel frame as being in the region of 80% to 95%. From a material performance point of view, there is no reason why the frame couldn’t be 100% reusable, but the report is realistic about logistical challenges and issues like unintentional damage to components.

As reuse gains more and more traction, the industry will go through a learning experience of how best to make it happen. At first, therefore, reuse rates are likely to be at the lower end of the estimate. What the Seismic platform has shown, however, is that by planning for reuse and putting a series of measures in place to help make sure it happens, construction platforms can aim for near-complete reuse of their steel frames.

The ’End-of-life waste routes and recommendations for Seismic II’  report is available to read in full. Find out more about the Seismic platform , and stay up to date on how Tata Steel is contributing to proving the concept of construction platforms by signing up to our newsletter .