Without question there is a gathering momentum for steel reuse in construction. This is hardly surprising as reused steel can offer huge carbon savings compared to virgin steel.  

We at CST have been participating in a number of projects that have been utilising reused sections. In this blog we want to share some of the learnings coming out of this exercise – some may seem relatively obvious, but some were less expected. 

In the current market, the desire for reuse is primarily coming from the client or asset owners and the supply chain is not yet well established nor fully stocked. This has led to large asset owners looking to their own buildings to recover the steel for reuse within their own projects. This is further incentivised by the fact that the majority of the carbon benefit is allocated to the recipient building, whereas the environmental “credit” for the demolished building is relatively minor. This causes a number of issues that must be addressed. 

Firstly, there is little precedent currently for designing buildings from available materials. Normally the building is designed to meet a clients needs and then to be made from readily available materials. 

Secondly, the free issuing of materials to a project is very unusual and this is disruptive to almost all aspects of the supply chain. In this scenario, engineers will be required to adapt loadings to materials presented, rather than finding materials to cope with loadings. Quantity surveyors will be told to use the free issue materials and supplement the rest with new. But with the yield from reuse being less predictable compared to buying all new materials, how do you give a firm project price?  

Connection design has to consider any existing holes and plates and possibly defects, and fabricators have to review their process to ensure rework can be done and the costs are covered. This all adds uncertainty and with that usually comes contingency in pricing. This must all be carefully considered to ensure costs are not inflated for peace of mind of the supply chain. 

Read more about what the second hand steel market might look like here

Thirdly, as the design is rarely confirmed at the start of a project then material requirements can change dramatically as the detailed design is finalised. On one occasion none of the material that was pre-selected was still required at the time of construction due to design changes. This is a nightmare for Quantity Surveyors and for the carbon calculations. 

Cost is a big factor as many projects take months or years to go from design to construction. If you want to secure materials at concept stage but the construction is 24 months later, the prices secured may bear no reflection on the market prices in force at the time. Moreover, if materials aren’t secured at the outset, they may not be available when they are required. Buying them early does provide price certainty but requires upfront cash and storage. What happens if the design changes? Traditional stockholding looks for quick turnover, the reused market moves much more slowly – it is a different beast. 

There are of course the obvious issues of compliance to standards such as EN1090 and cosmetic acceptability, but as most steel work is hidden after construction, should we allow some cosmetic variability prevent reuse? This must be explained to clients. 

The market place is changing fast and the appetite for steel reuse is significant, but thankfully the quantity of material that could potentially be available is also large, but we need to get it out from demolition and into the supply chain. The market has been slow to develop as demand was low but now that demand has risen there is no doubt that the supply chain will adapt, and business models will evolve. As keen as the market is to have reused materials in their new buildings they must first look to “feed” the market with the materials arising from old assets when they are demolished. Property owners can ensure demolition specifications are circular and this needn’t come at any cost.  

The materials may be old, but the innovation and entrepreneurship required is just as exciting as new product development. 

This blog post is inspired and supported by two case studies provided by Cleveland Steel and Tubes, which you can find here: