Energy management

See a full summary of our energy consumption data (PDF) .

In typical operating conditions, energy consumption is our second largest source of greenhouse gas (GHG) emissions (approximately 8.5% in FY24). We use a multi-faceted strategy to minimise energy consumed by our UK sites and related emissions. These measures comprise:

• Reducing consumption through investing in energy efficiency measures.
• A 10-year Virtual Power Purchase Agreement to procure zero carbon electricity.
• Purchasing certified renewable biogas.
• Removing and offsetting carbon in line with our global decarbonisation targets (PDF).

Technologies we employ to minimise energy consumption in our buildings include: 

• Building Energy Management Systems for virtual metering and optimisation.
• Thermostatic office temperature controls.
• Upgraded chillers for communications rooms and set point controls.
• LED lighting, digital controls and zonal passive infrared (PIR) sensors.
• Upgrades to fan coil unit (FCU) and air handling unit (AHU) systems.
• Replacement boiler plant and water heaters.
• Energy efficient IT equipment including monitors with stand-by mode. 
• Lift destination control software. 
• Print, vending and other devices utilising sleep mode during low demand periods. 

Our Technical Services team closely monitors energy consumption and conducts energy audits across our UK estate to identify opportunities for savings. When our offices undergo refurbishment or relocation, our technical standards and specifications dictate that all building services and systems must align with current energy efficiency best practice. 

Renewable energy

In FY25, 100% of Ernst & Young LLP (EY UK) energy consumption was backed by renewables certification. This was achieved through a combination of Renewable Energy Guarantees of Origin (REGO) certificates received via our UK Virtual Power Purchase Agreement (VPPA), renewable energy supplied by our landlords and our continued purchase of renewable biogas. 

Our VPPA is also helping to decarbonise the UK energy sector, by adding more renewable electricity into the national grid than we consume. 

Performance against our FY25 targets 

Target: Reduce total energy (kWh) consumed by 15% per m2 (compared to FY19) 

FY25 energy efficiency (kWh per m2) fell by 24.7% compared to FY19. The reporting period saw a notable uplift in the occupancy levels of UK offices compared to the previous year – notably at our largest office (More London Place) where building occupancy increased by 9%. However, FY25 consumption per head (i.e. kWh / FTE) at this site decreased by 1.3%. As the lease end date for this site approaches, we will consider utilising ground / air source heat pumps to reduce energy consumption beyond that already achieved, following previous lighting, plant and equipment upgrades.

Short-term opportunities for implementing further energy efficiency measures across the UK estate are somewhat limited, as most Heating, Ventilation and Air Conditioning (HVAC) plant servicing buildings where our offices are located is owned and operated by the landlord. However, we remain committed to reducing energy consumption wherever possible and will upgrade to low-energy LED lighting in our Bristol and Luton offices during 2025.

In July 2024, our Cambridge office relocated to state-of-the-art premises in Cambridge Square. Our Leeds operations moved to a new low-energy site in Wellington Place in September 2024, having building-specific energy targets and performance monitoring in place. Our third largest UK office (Birmingham) will move to new energy-efficient premises. We therefore expect to see reduced energy consumption for these UK offices during FY26.

*FY19 is the base year, as determined by EY Global when setting its Global Carbon Ambition and related energy reduction targets for member firms.

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