Investment management giant BlackRock has demonstrated the potential of circular lighting upgrades by refurbishing thousands of existing luminaires at its London headquarters rather than replacing them entirely.
The project involved the upgrade of 2,400 T5 fluorescent luminaires across the firm’s 13-storey office building. Operating continuously, the lighting system ran for 8,760 hours per year and consumed more than 900,000kWh of electricity annually.
Instead of replacing the luminaires, Smart Systems UK developed a bespoke LED gear tray that could be installed within the existing fittings. The solution retained the luminaire housings while replacing the fluorescent lamps and control gear with LED modules and drivers, significantly extending the useful life of the installed lighting infrastructure.
The replacement gear trays were designed to match the lighting performance of the original T5 system while reducing both energy consumption and heat output. Developed in collaboration with the project’s electrical contractor, the trays were engineered for rapid installation during night-time working hours, minimising disruption to building operations.
The original luminaires consumed 43W each, including ballast losses. Following the upgrade, power consumption fell to 20W per fitting, delivering an energy reduction of 53 per cent
Annual electricity consumption was reduced by 483,552kWh, cutting lighting costs by more than £50,000 per year. Over the minimum 50,000-hour design life of the LED modules, the project is expected to save around £254,000 in energy costs.
Additional savings arise from reduced maintenance requirements. The LED modules and drivers carry a five-year, 50,000-hour warranty, eliminating much of the lamp and ballast replacement previously required. Over the same period, maintenance savings are estimated at £122,400.
Combined energy and maintenance savings are expected to exceed £376,000 during the first five years of operation.
The project highlights how luminaire refurbishment can deliver many of the benefits of an LED upgrade while retaining existing assets. By reusing luminaire bodies and replacing only the components that determine performance, organisations can reduce material consumption, avoid unnecessary waste and lower the embodied carbon associated with a full luminaire replacement programme.
As the lighting industry increasingly embraces circular economy principles, projects such as this demonstrate the value of upgrading and extending the life of existing lighting assets wherever technically feasible.
• Learn more sustainable lighting at Circular Lighting Live 2026, Recolight’s flagship conference and exhibition, which takes place on Thursday 8 October 2026 at the Minster Building in the City of London. Free to specifiers, Circular Lighting Live 2025 will feature leading experts, specifiers and policy makers who will share their insights into forthcoming standards and legislation, emerging technologies and new business models. More info: www.circularlighting.live
