Reuse starts with the question many projects fail to ask at Stage 1

In the past 20 years, I have never had someone come to me at RIBA Stage 1 or 2 and ask to explore circularity. I've written before that by Stage 3 it is often too late. The truth is that, on most projects, the conversation hasn't started by then at all.

When it does arrive, the brief is fixed and the procurement route is set. The only question left is whether reuse can be added without disrupting anything. Usually it can't.

That was the thread running through the panel we hosted at the British Science Festival in Southampton in September. An academic, an investor-developer, an engineer, a manufacturer, a materials marketplace, a consultant and a contractor came at circularity from different directions and kept arriving at the same place. The barrier to reuse is rarely technical. It is the question nobody asks early enough: what do we already have?

Reuse is a skill we've forgotten, not one we need to invent

Gareth Atkinson, Director at Civic Engineers and co-founder of the Engineers Reuse Collective, reminded us that circularity is not new. Buildings were once dismantled and salvaged, and ships taken apart for their materials, because materials were valuable. Cheap fossil fuels and industrial manufacturing changed those economics.

Professor AbuBakr Bahaj of the University of Southampton framed the goal plainly: keeping resources in use for as long as possible. We are a long way off. The Circularity Gap Report puts the share of the global economy's materials that come back round at under 7%, roughly one tonne in 14. The task is not invention. It is making reuse practical and economic again, inside a system built around new.

What TBC.London taught us about designing to stock

We learned this first-hand at TBC.London, the retrofit of a 1990s office near Tower Bridge that we delivered for FORE Partnership. Sixteen tonnes of 1930s steel beams came out of the former House of Fraser store on Oxford Street and went into the new structure, saving 48 tonnes of embodied carbon against virgin steel.

The steel is the headline. The process is the lesson. Riveted beams and steel encased in concrete couldn't be used. Anything older than the 1970s had to be tested and recertified. Fabrication drawings had to be matched to what was actually in stock, rather than stock being ordered to match the drawings.

That last point is the one I want every client to understand. Reuse turns the normal design sequence around: you start with what exists and design to it. That only works if the decision is made before the design has hardened around new materials.

The brief-holder decides whether reuse survives

Basil Demeroutis, Managing Partner at FORE, was clear about where responsibility sits: with the people who hold the brief and control the budget. Circularity is rarely abandoned by an engineer. It gets cut in value engineering, when reclaimed materials look like risk and new ones look like certainty.

That is why the commercial plumbing matters. Rob Smith, Managing Director of Material Index, explained how making reclaimed and refurbished materials easier to find gives them a realistic route back into projects. Martyn Wright, Sustainability and Circularity Consultant at Technal UK, pressed on a question procurement rarely answers: what happens to materials, and who owns them? Until contracts answer that, reuse remains a favour rather than a requirement.

Diversion is not the same as circularity

We should be honest about our own numbers too. Willmott Dixon diverts 97% of its non-hazardous waste from landfill and has cut construction waste by 51% against its 2018 baseline. I'm proud of both.

But diversion tells you where material went, not whether it kept its value. The measure I would rather our industry was judged on is harder: how much of what we build with was already in use.

Ask early, then show the working

Abby Foster, Sustainability Partner at Ridge and Partners, made a point that stayed with me. People in technical roles are not always good at explaining what they do. That matters, because circularity stays abstract until people can see it working. Projects like TBC.London only change minds if we share the detail, including what didn't work.

So my ask of customers and their advisers is simple. Before the brief is fixed, ask what already exists: in the building you are replacing, in the one down the road, in a supplier's yard. Not everything should be reused. But new should stop being the automatic answer.

None of this needs a breakthrough. It needs someone in the room to ask the question while the answer can still change the design. Bring us in early enough, and that someone can be us.

NOTE:

The panel was hosted by Willmott Dixon in partnership with the University of Southampton and the British Science Association at the British Science Festival 2026 (16–20 September, Southampton). With thanks to: Professor AbuBakr Bahaj, Professor of Sustainable Energy, University of Southampton; Basil Demeroutis, Managing Partner, FORE Partnership; Gareth Atkinson, Director, Civic Engineers and Co-Founder, Engineers Reuse Collective; Abby Foster, Sustainability Partner, Ridge and Partners LLP; Rob Smith, Managing Director, Material Index; Martyn Wright, Sustainability and Circularity Consultant, Technal UK; and Kemi Owoeye, Technical Lead for Sustainable Design, Willmott Dixon.