A Quantum leap at 8 Bishopsgate

Standing 204 metres above the City of London, 8 Bishopsgate is one of the capital’s most recognisable new commercial towers. Designed by WilkinsonEyre and delivered by Lendlease, the 51-storey development provides over 52,900m² of Grade A office accommodation, retail space, landscaped terraces and a public viewing gallery, all while achieving BREEAM Outstanding and EPC A ratings.

Sustainability was central to the project’s design. Structural efficiencies reduced steel use by 25%, saving around 5,000 tonnes of CO₂, while an innovative raft foundation reduced concrete requirements by approximately 3,000m³. The tower’s distinctive stepped form also creates generous roof terraces that enhance occupant wellbeing and biodiversity.

Radmat played a significant role in delivering the complex roofing package across the development. At the heart of the solution was the ProTherm Quantum® PLUS+ VIP Inverted Roof System, combined with ProTherm XPS Infill Insulation, enabling exceptionally low roof build-ups while maintaining demanding thermal performance and achieving the required level thresholds. The system delivered an overall U-value of 0.25 W/m²K, even in challenging areas beneath BMU tracks and rooftop plant where height restrictions and irregular detailing would normally compromise insulation performance.

Radmat’s Blue Roof System also formed a key part of the building’s sustainable drainage strategy. Designed specifically for constrained urban developments, the system temporarily stores rainfall for up to 24 hours before releasing it at a controlled rate, helping the project meet SuDS requirements without the need for extensive underground attenuation tanks. Waterproofing was provided by PermaQuik Hot Melt Monolithic Membrane and EshaFlex 370 Reinforced Bitumen Membrane, delivering robust long-term protection across all six blue roof areas.

The completed project demonstrates how innovative roofing systems can overcome demanding technical constraints while contributing to sustainability, building performance and long-term resilience. At 8 Bishopsgate, Radmat’s integrated waterproofing, insulation and blue roof solutions helped deliver one of London’s most technically advanced commercial developments.