About the company

As one of Northern Ireland’s leading suppliers of essential construction materials, Northstone Materials operates in a carbon-intensive sector where the transition to a low-carbon economy is both a challenge and a responsibility. With a long-standing heritage and deep connection to the region, Northstone recognises the critical role it plays in shaping the built environment and supporting sustainable infrastructure.

Aligned with the wider CRH Group’s sustainability strategy, Northstone has prioritised Decarbonisation, Circularity, and Water Stewardship as the core pillars of its approach. These priorities are embedded within a wider commitment to environmental, social, and economic sustainability, enhancing biodiversity, creating social value, and ensuring long-term resilience across its operations and supply chain.

Northstone’s inclusion in Business in the Community’s Top 40 Environmental Benchmarking Survey and achievement of Platinum Award status reflects its position as a sector leader in sustainable materials and responsible quarrying practices in Northern Ireland.

What the company did

Over the past five years, Northstone has taken a strategic, data-driven approach to embedding sustainability into its core operations, moving beyond compliance to deliver measurable, transformational change.

Recognising the environmental impact of its sector, the business has focused on:

• Integrating sustainability into operational decision-making
• Driving efficiency and innovation across production processes
• Setting clear, ambitious, and science-aligned targets
• Ensuring transparency, accountability, and continuous improvement

Through targeted investment, employee engagement, and process optimisation, Northstone has successfully balanced operational performance with long-term environmental stewardship, strengthening resilience while maintaining product quality and delivering value for customers and communities.

Crucially, Northstone is also using its position within the construction supply chain to influence lower-carbon practices across the built environment, supporting customers in reducing embodied carbon and increasing the use of sustainable materials.

Impacts and Outcomes

Carbon Reduction and Decarbonisation

Northstone has demonstrated sector-leading progress in reducing operational emissions:

• Developed a 2030 CO₂ Roadmap to guide decarbonisation across all operations
• Achieved a 33% reduction in Scope 1 emissions (7,424 tCO₂e) from baseline

Implemented key measures including:

• Fuel management systems
• Energy efficiency training for operatives
• Optimisation of plant and machinery

Product innovation has also delivered significant carbon savings:

• Reduced cement content at four ready-mix concrete plants from 304.8 kg/m³ (2021) to 288.9 kg/m³ (2025)
• Delivered 921 tCO₂e in embodied carbon savings
• These actions position Northstone ahead of industry expectations, demonstrating what is possible within a traditionally high-emission sector

Circular Economy and Resource Efficiency

Northstone is actively reducing reliance on primary raw materials and embedding circular principles across operations:

• Increased use of Ground Granulated Blast Furnace Slag (GGBS) from 1,518 tonnes (2024) to 2,737.85 tonnes (2025) to produce a low CO₂ concrete range
• Expanded Recycled Asphalt Planings (RAP) usage to 7,404.10 tonnes (YTD April 2026), up from 4,545.12 tonnes (2025)
• Achieved Paragraph 40 Waste Exemptions, enabling responsible handling of coal tar asphalt
• Recycled approximately 25,000 tonnes of roof tiles into high-quality secondary aggregates
• These initiatives demonstrate clear year-on-year improvement and reinforce Northstone’s role in driving circularity within the construction sector

Water Stewardship

Significant progress has been made in reducing operational water consumption and improving resource management:

• Reduced water usage from 468,261 m³ (2024) to 296,368 m³ (2025)
• Implemented enhanced metering and digital monitoring systems
• Maintained rainwater harvesting systems at key facilities
• Continued review and optimisation of water management practices
• This proactive approach ensures efficient water use while safeguarding local resources, particularly in environmentally sensitive areas

Biodiversity and Community Impact

Northstone recognises that sustainable operations extend beyond its sites and into the communities it serves:

• Developed Biodiversity Action Plans across sites
• Created nature trails and woodland habitats, enhancing local ecosystems
• Introduced QR-enabled wildlife monitoring systems to engage employees
• Supported environmental initiatives at Lough Neagh, including litter picking and invasive species removal

These actions demonstrate Northstone’s commitment to delivering social and environmental value alongside economic performance, strengthening its relationship with local communities.

Leadership in Action

Northstone’s achievements reflect a business that is not only improving its own performance but also helping to shape the future of sustainable construction in Northern Ireland.

“At Northstone, we recognise that the materials we produce today will shape the infrastructure and communities of tomorrow. That is why we are taking decisive action to reduce carbon, improve resource efficiency, and work collaboratively with our customers and supply chain to accelerate the transition to more sustainable construction. As a key part of the built environment, we are committed to delivering lasting, positive impact for generations to come.” (Darren McMillan – Managing Director)

Conclusion

Through measurable progress, strategic alignment, and a commitment to continuous improvement, Northstone Materials has established itself as a benchmark for sustainability in the mining and quarrying sector.

Its Top 40 ranking and Platinum status in the Environmental Benchmarking Survey reflect not only strong performance but also genuine leadership, demonstrating how responsible business practices can drive meaningful environmental and societal change.