Sentinel was invited to join a major contractor on the ambitious reworking of a 1980s office building into 500,000 sq ft of prime modern office space, incorporating well-being facilities like a gym and swimming pool. The project retained 75% of the primary structure and prioritised sustainability, all while operating in the heart of London’s financial district, where noise and environmental restrictions are strictly enforced.
The building was stripped back to bare steel, requiring structural steel cleaning and intumescent fire protection. Strict noise, dust, and environmental restrictions limited traditional construction methods.
The project demanded a solution that:
– Reduced dust contamination during cleaning
– Minimized environmental impact
– Decreased disposal of contaminated waste
Innovative Laser Cleaning: First-of-its-kind solution for Skanska in UK construction
Reduced emissions and landfill waste by ~90%
Minimized dust, noise, and environmental disruption
Water-Based Intumescent Paint System:
– Low Volatile Organic Compounds (VOC), classified as trace
– Applied on-site, enhancing WELL compliance for Skanska
– Stronger alignment with sustainable construction goals
Environmental Impact: Laser cleaning vs traditional shot blasting drastically reduced waste, emissions, dust, and noise.
– Sustainability:
– Supported circular economy and ESG targets
– Resource-efficient and landfill-minimizing
| Aspect | Shot Blasting | Laser Cleaning |
| Waste | 236 tonnes | 25 tonnes (211 tonnes avoided) |
| Carbon Emissions | 288,000 kg CO₂e | 30,580 kg CO₂e (~89% cut) |
| Dust & Noise | High | Minimal |
| Precision | Aggressive, damaging | Controlled, protects |
| Speed | Slow, due to buildup | Fast, streamlined |
| Sustainability | Resource-intensive & landfill-dependent | ESG-aligned, supports circular economy |
Sentinel’s innovative approach delivered significant environmental savings, streamlined operations, and strengthened Skanska’s sustainability and WELL obligations, making 1 Appold Street a benchmark project for modern, responsible office construction in London.
Mark Stewart, Director, Sentinel Contracting plc, says: “This project has shown the huge reduction in environmental impact that can be achieved. Our innovative sponge media blasting solution has reduced landfill costs alone by £105,000 and the low VOC Intumescent Paint System reduces the environmental impact to air quality by 40%. By using this method, the construction industry can achieve 80% less product, 80% less landfill, 80% less delivery cost and 80% less disposal cost.”
Sentinel was invited to join a major contractor on the ambitious reworking of a 1980s office building into 500,000 sq ft of prime modern office space, incorporating well-being facilities like a gym and swimming pool.
Sentinel Contracting was engaged by Knight Harwood to provide specialist decorating services for The Whittington Building. To complement, we selected Dulux Trade paints for both interior walls and high-traffic areas.
This is a famous building in the heart of St James’s that was in the process of being totally redeveloped. Our painting and fireproofing solutions played a healthy part in the successful completion of the project.
The redevelopment of Battersea Power Station was one of the biggest regeneration projects in London in recent decades. We were engaged to install the soffit system on a scheme that revitalised this London industrial icon.
Sentinel partners with Laser
Cleaner. Faster. Safer. Smarter. When it comes to restoring structural steel, laser cleaning isn’t just an upgrade, it’s a revolution. And Sentinel is the only contractor in the UK currently offering this precision-engineered service at scale.
Sentinel Contracting plc
Unit 2a Guildprime Business Centre, Southend Road Billericay, Essex CM11 2PZ
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Cumbria Office: 26 Market Place, Cockermouth, Cumbria, CA13 9NQ
