Reusing Existing Infrastructure: Cost, Carbon and Constructability
Reusing existing structures and assets is one of the most effective ways to reduce both cost and embodied carbon — provided constructability is assessed honestly, not optimistically.
Marcel Mbene, ChPP — Founder, Bold Leverage Ltd · 13 July 2026
The appeal is genuine
Demolishing and rebuilding is carbon- and cost-intensive: new materials, new foundations, and the embodied carbon of the structure being removed is simply lost. Reusing existing infrastructure — a structure, a foundation, an item of plant, a section of network — can avoid a significant share of that cost and carbon in one decision. It is one of the few sustainability measures that also tends to improve the business case, which is why it deserves serious consideration on almost every project involving existing assets.
Why reuse decisions go wrong
The risk is that the decision to reuse is often made before the condition of the asset is properly understood. Existing structures may have deteriorated in ways that are not visible without intrusive investigation. Historical drawings may not reflect what was actually built. Capacity that was adequate for the original design life may not meet current standards or the demands of a new use.
When these factors are discovered after the reuse decision has been committed to programme and budget, the project faces a difficult choice: accept a compromised solution, or absorb the cost and delay of reverting to new-build partway through delivery.
Assessing reuse honestly
A credible reuse assessment starts with intrusive survey and condition assessment, not just a desk-based review of existing records. It tests the asset against current standards, not only its original design basis. And it builds contingency into the programme and cost plan to reflect the genuine uncertainty that exists until physical investigation is complete — rather than assuming the best case and hoping it holds.
Constructability also needs early attention: reused assets often impose real constraints on how new work can be sequenced and accessed, and those constraints need to shape the design rather than being discovered by the contractor on site.
Our view
Reuse should be pursued wherever it is genuinely viable — the cost and carbon case is usually strong. But the viability question needs to be answered with evidence, early, rather than assumed. This is a recurring focus of our engineering consultancy and infrastructure advisory work on projects involving existing assets.