6 Gracechurch Street Sustainability

As part of Quadrant’s strategy to future-proof 6 Gracechurch Street and improve its ESG performance, a major decarbonisation programme was undertaken to reduce the building’s reliance on fossil fuels and enhance its long-term sustainability credentials. The initiative focused on modernising the building’s ageing mechanical infrastructure and creating a pathway towards a fully electric heating and cooling system.

Technical assessments identified replacement of the existing gas-fired heating and cooling plant as the most effective means of reducing operational carbon emissions and improving environmental performance. The chosen solution involved replacing the existing chillers with roof-mounted electric air source heat pumps (ASHPs), providing a highly efficient low-carbon system capable of delivering both heating and cooling.

The new ASHP installation was designed to support a phased transition away from gas. Initially, the system reduced reliance on the existing boilers while providing cooling across the building. Over time, heating distribution systems, including fan coil units and air handling equipment, can be upgraded to operate efficiently at lower temperatures, enabling the eventual decommissioning of the gas boilers and full electrification of the building’s heating system.

The project also included wider building services improvements, notably upgrades to the building management system and reviews of the electrical infrastructure to ensure the property could support increased electrical demand associated with heat pump technology.

Implemented whilst the building remained occupied and fully operational, the works were completed during 2026. The project has resulted in significantly enhancing the building’s sustainability credentials, reducing operational carbon emissions, improved resilience to future regulatory requirements and strengthened its appeal to occupiers seeking high-quality, environmentally responsible office accommodation. The project demonstrates how targeted investment in building infrastructure can preserve long-term asset value while supporting the transition to a lower-carbon built environment.