Sustainability Report
Embodied carbon
Performance: Stonecutter achieved 538 kg CO2e/m² embodied carbon versus the London Plan benchmark of 950 kg CO2e/m². It is the first office building to deliver the City of London’s “Aspirational” target for as-built embodied carbon.
Whole-life carbon: Predicted 263 kg CO2 per person.
Materials:
- Steel: Two-thirds produced in electric arc furnaces, delivering 60 percent embodied carbon savings compared to blast furnace methods.
- Concrete: 40–60 percent cement replacement, improving on 30 percent industry standard.
- External stone: Moca Cream Medium Grain (LSI Stone) with Environmental Product Declaration (EPD) available on request.
- Aluminium framing: 30 percent pre-consumer recycled aluminium (Focchi).
- Feature wall rendering: Clay aggregates from Cornwall (Clayworks).
- Signage: Bamboo (xsign) in place of plastic.
Structural system: Lightweight frame with 13.5 m x 9 m grids, reducing embodied carbon by 60 percent compared to benchmarks.
Operational Emissions / Energy
Systems: Fully electric-powered, with no gas. Efficient air-sourced cooling, enhanced insulation, 2,700 square feet of solar panels, and advanced ventilation with energy recovery.
Envelope: Facades designed to minimise ventilation loads.
Performance metrics:
- Airtightness at 50Pa: 2.66 m³/h.m²
- Heating load: 2.08 kWh/m²/yr
- Water load: 8.03 kWh/m²/yr
- Total energy load: predicted 43.42 kWh/m²/yr; actual 30.32 kWh/m²/yr
- Area-weighted U-value: 0.83 W/m²K
Certifications: Aligns with BREEAM and WELL, and follows the CRREM pathway (Carbon Risk Real Estate Monitor — a science-based framework to decarbonise real estate in line with the Paris Accord).
Monitoring: Smart building technology enables occupiers to track and manage energy usage.
Service and maintenance emissions
Elements such as cladding and glazing have specified design lives (30 and 25 years respectively), ensuring they can be replaced, recycled, or upgraded systematically.
In addition, rainwater harvesting, extensive green roofing, and biodiversity gardens reinforce a sustainable, circular approach to resources across the life of the building.
Afterlife
Stonecutter was designed with adaptability at its core. The lightweight structural system with wide 13.5 m x 9 m grids creates virtually column-free floorplates. Spaces are easily reconfigured to meet changing tenant needs or even entirely new programmes in the future.
The podium level was deliberately conceived as a flexible zone, able to transform between a business lounge, additional retail, or a dedicated reception space.
Efficient, naturally lit floorplates further support a diverse occupier base, from technology firms to creative industries and financial services.
The project integrates circular economy principles from the outset. Major structural materials were chosen for their recyclability and responsible sourcing, including electric arc furnace steel, low-carbon concrete, and recycled-content aluminium framing. At the end of the building’s life, these elements can be recovered and re-enter the material cycle rather than being wasted.
Key products in low carbon design
