Talk and practice

Britain’s construction sector talks confidently about the circular economy. It is less confident about who is accountable once a project changes hands.

Most contracts are designed to end. Responsibility ends with them.

A widely cited industry piece puts the prize for a circular built environment at around £1.5 trillion. The figure assumes materials reused, buildings maintained for longer, waste redirected. It is a systems claim. It requires systems cooperation.

Britain’s contracts do not deliver that. Designers pass the asset to contractors. Contractors pass it to facilities managers. Maintenance lands wherever an asset is owned at the time. At each boundary, a legal duty expires.

This is the gap the conversation returns to.

Engineer by training

Amira read Civil Engineering at Cambridge, graduating with an MEng in 2018. She is chartered with both the Institution of Civil Engineers and the Institution of Structural Engineers.

Before her own practice, she moved through several firms, including AECOM, Walsh Structural and Civil Engineers, Morph Structures, Fairhurst and AMP Structures. Her work has spanned new build and retrofit, from early design through construction.

In May 2025 she founded Additive Sustainability. Its premise is straightforward.

Push materials, embodied carbon and maintenance thinking into the earliest design decisions, rather than leaving them to procurement.

A pair of shoes

Amira tells a story about shoes. As a teenager she wore through a pair and left them downstairs to throw away, having already ordered replacements. Her mother intervened and took them to a cobbler.

“It changed the way I thought about everything.”

She had not considered where the shoes were made, nor where they would have gone. A small local skill had extended their life. Construction, she argues, has the same blind spot writ large. Every project is treated as a blank canvas. Existing stock is framed as constraint.

“What do we perceive as valuable?”

Heritage or worn. Vintage or old. The commercial case for reuse rests on which word applies.

Thinking moved upstream

Additive Sustainability works to move structural and material decisions to the front of projects. By the time most designs are fixed, the embodied carbon is already committed.

The practice assesses existing buildings for continued use. It advises on extending the life of assets rather than replacing them. It specifies reclaimed or low carbon materials. It sets carbon budgets within which contractors must procure.

It also redirects physical stock, including timber, steel and concrete, from sites being stripped out to sites that can use them.

Amira prefers the phrase asset maintenance to circular economy.

An asset, in her framing, is something that yields future value, requires upkeep, and has stakeholders who use it.

The language matters. It turns a building from a finished deliverable into a continuing obligation.

Where contracts end

The obligation has no contractual home.

“I’ve not really worked on a project where we are looking at maintenance and repair.”

Construction contracts terminate at defined handover points. The designer’s duty ends. The contractor’s duty ends. A facilities manager’s duty begins. None of these parties carries a financial stake in what happens across a building’s full life.

Circularity requires that stake.

“Someone’s contract ends and someone’s contract begins.”

The larger contractors do this better, she says. They are resourced for it. They staff sustainability teams. They win regulated work that mandates it.

“The bigger players are doing it better.” They are, she adds, because they have to.

Smaller firms face different economics. Their clients do not demand circular methods. Their contracts do not price them. Voluntary adoption is limited.

“If it’s an option, people aren’t going to do it.”

There is also the cost asymmetry. Reclaimed and recycled materials tend to cost more than virgin supply. Procurement logic weighted to the short term will keep choosing virgin material until that calculation changes. Incentives, she suggests, work better than penalties within existing contract cultures. A VAT cut on reclaimed material would help. It would not suffice.

Then there is the short termism of the wider framework. Circularity is a long horizon bet. Listed developers are not. When put to her that shareholder pressure actively rewards building for short lifespans, she does not disagree.

“Unfortunately, I have to largely agree with what you said.”

A question of responsibility

Given one intervention, Amira returned to accountability. Designers, she said, should remain responsible for the buildings they designed long after handover. Producers should be responsible for what happens to materials at end of life.

“We have responsibility of the end of life.”

The current system is organised to do the opposite. It releases every party from the asset as their contract closes. This is not an oversight. It is a feature of how the sector is priced, contracted and financed.

Whether it changes depends on contract design, tax treatment, client demand and the allocation of capital. None of those levers sits with a structural engineer. They sit with regulators, investors and the C suites that, in her reading, understand the problem best where they are compelled to.

The gap between rhetorical ambition and structural accountability remains open.