OPINION: Incinerator Bottom Ash (IBA) is fast becoming a focal point in the conversation around sustainable construction, waste reduction and carbon policy. Sitting at the intersection of these agendas, it represents both a major opportunity and a complex challenge.
Through recent conversations with clients heavily involved in IBA recovery and reuse, it’s clear this is no longer a niche material, it’s emerging as a strategic resource in the transition to a circular, low-carbon economy.
The Opportunity Beneath the Ash
IBA, the mineral residue from Energy from Waste incineration offers a viable, low-carbon alternative to virgin aggregates. Around 1.4 million tonnes of IBA is produced annually in the UK, much of which can replace natural materials in road building, concrete and civil engineering.
The benefits are substantial. Up to 95% could be diverted from landfill if fully reused, cutting emissions by as much as 50% compared with quarry-derived materials. In some applications, IBA can replace up to 60% of aggregate, easing pressure on natural resources while lowering embodied carbon.
For waste operators, IBA offers a new revenue stream; for construction firms, it’s a sustainable and cost-effective material that aligns with ESG goals.
Challenges and Considerations
Despite its promise, IBA adoption remains uneven. Composition varies by feedstock and process, requiring strict quality control and consistent standards. Regulation is fragmented, with regional differences in classification and approval.
Perception is another hurdle. Though performance data is strong, IBA still faces resistance as a “waste-derived” material. Overcoming that requires transparency, standardisation and visible success stories that prove its safety and value at scale.
Drivers of Change: Policy, Demand, and Innovation
IBA’s growth is being driven by three forces:
- Policy pressure: Net-zero and circular economy targets demanding resource recovery.
- Market demand: Infrastructure expansion fuelling the need for sustainable aggregates.
- Innovation: New processing technologies improving quality, consistency and reliability.
Together, these trends are turning IBA from a disposal issue into a key enabler of circular construction.
Looking Ahead
To unlock its full potential, collaboration is essential, aligning regulation, investing in infrastructure and building trust across the value chain.
IBA may have started as a by-product of Waste to Energy, but it’s fast becoming a cornerstone of circular construction. For those willing to lead, it offers not just a sustainability win, but a genuine competitive advantage.
Subscribe for free