New RESTOR Paper Shows How Logistics Can Make or Break Steel Reuse

Structural steel reuse is one of the most promising ways to reduce the environmental impact of construction. Steel is already widely recycled, but direct reuse remains limited, even though it can avoid the energy-intensive process of remelting and manufacturing new steel. A new paper from the RESTOR project team, published in the Journal of Constructional Steel Research, investigates a key question: when does reused steel genuinely deliver environmental benefits, and when can practical constraints reduce those benefits? 

The paper, “Optimised steel frame design using reclaimed steel: Logistics impact on reuse efficiency,” was authored by Mohammad Ali Mahdavipour, Asaad Faramarzi, Samir Dirar, Marios Theofanous, Shima Jowhari Moghadam, Qixian Feng, Soheila Kookalani, Erika Parn, and Ioannis Brilakis. It forms part of the EPSRC-funded REuse of Structural sTeel in cOnstRuction — RESTOR project. Supported by industrial advisory partners Chetwoods Architects and Cleveland Steel.

The research develops a sustainability-driven optimisation framework for designing steel frames using both new and reclaimed steel. Rather than simply choosing the lightest steel frame, the framework considers the full environmental impact of different decisions, including demolition, deconstruction, reconditioning, fabrication, assembly, waste handling, and transport. The method uses Mixed-Integer Linear Programming, allowing the design process to select the best combination of new and reused steel members while still meeting structural performance requirements.

The team tested the approach on a benchmark four-storey steel frame and examined 625 simulated reclaimed steel stock scenarios. These scenarios varied the availability, length, oversizing, and damage condition of reclaimed members, as well as transport distances. This allowed the researchers to explore how real-world uncertainty affects the reuse of structural steel.

Key findings from the RESTOR paper

1. Reclaimed steel can significantly reduce environmental impact.When reclaimed steel members had suitable lengths and section sizes, optimised designs reduced total environmental impact by 64–67% compared with designs using standard new steel. This confirms the strong potential of steel reuse when reclaimed elements are well matched to project requirements.

2. Transport distance is critical.The environmental benefit of reuse is highly sensitive to logistics. Increasing the prefabrication transport distance for reclaimed steel by 800 km reduced its environmental advantage by up to 31% on average. This means local sourcing and efficient stock logistics are essential if reclaimed steel is to deliver its full sustainability benefit.

3. Reuse rate alone is not enough. A design using 100% reclaimed steel is not automatically the best environmental option. If reclaimed members are poorly matched or oversized, the frame may become unnecessarily heavy, increasing fabrication, transport, and handling impacts. The study shows that environmental optimisation must consider both reuse rate and the suitability of available stock.

4. Some oversizing can still be acceptable.Because reclaimed steel already carries embodied value from its first life, using a slightly heavier reused section can still be environmentally preferable to manufacturing new steel. However, the paper identifies threshold ranges where oversizing remains efficient, showing that design decisions must balance reuse ambition with material efficiency.

5. Excluding damaged steel can increase environmental impact.The study found that removing damaged reclaimed members from the available stock can increase environmental impact by up to 46% in some scenarios. This does not mean damaged steel should be reused without assessment. Instead, it highlights the need for better testing, certification, and performance-based guidance so that safe and usable reclaimed components are not unnecessarily discarded.

6. Structural design criteria matter. Higher live loads and stricter deflection limits increased environmental impact, because they require stockier sections. However, the study also shows that closer coordination between structural and architectural design could help reduce unnecessary environmental penalties, for example by allowing appropriate flexibility in non-structural components.

Why this matters

The findings show that steel reuse is not simply a material substitution problem. It is a systems problem involving design optimisation, logistics, stock databases, structural assessment, certification, and supply chain coordination. For industry, this means that future steel reuse workflows need to connect engineering design with digital inventories, transport planning, non-destructive testing, and environmental assessment.

For Project RESTOR, this paper provides important evidence that digital tools and optimisation methods can help move reclaimed steel from an uncertain, manually managed resource into a more reliable design option. By understanding how stock quality, member dimensions, transport distance, and damage affect environmental performance, the construction industry can make better decisions about when and how to reuse steel.

Ultimately, the research supports RESTOR’s wider mission: to enable a more circular steel construction sector where structural components are not automatically recycled or scrapped, but are assessed, optimised, and reused wherever safe and environmentally beneficial.

Published paper URL: https://doi.org/10.1016/j.jcsr.2025.110046

ScienceDirect: https://www.sciencedirect.com/science/article/pii/S0143974X25007242