British Land and Sir Robert Mc Alpine have delivered the next significant stage as part of their 10-year redevelopment of the Broadgate framework. The 520,000sq ft development designed by Hopkins Architects, in collaboration with Universal Design Studio includes 490,000sq ft of light airy office space, 90,000sq ft of new shops, boutiques and restaurants across 3 levels, with the addition of a ninth-floor restaurant with terraces for alfresco evenings. 20,000sq ft of outdoor terraces were also built into the complex across 5 levels, designed with bright, colourful gardens to attract more birds, butterflies and bees to Broadgate.

With the intention to prioritise sustainability and environmental consideration, 100 Liverpool Street is British Land’s first net zero carbon development. Reaching this achievement involved retaining over 50% of the original structure from 1988, including all of its foundations. This resulted in 7,521 tonnes of carbon, additionally using recycled waste aggregates in place of concretes and cement while optimising light and heat where possible also aided the development’s environmentally friendly nature. 100 Liverpool Street achieved a remarkable Outstanding BREEAM score, with a final post-construction certification of 89.2%

Radmat Building Products for Lindner Prater, were tasked with providing exceptional insulation and waterproofing to accompany a unique design shape and protection for multiple rooftop terraces. Each level of 100 Liverpool Street features unique curves, which allows more sunlight for people relaxing in the Broadgate Circle. This creative thinking and smart design leaves a complex situation with insulation. Radmat’s ProTherm Quantum^® PLUS⁺ VIP inverted roof system was the ideal solution, as it supplies exceptional thermal outcome while completely minimising space.

The building’s elegant, curved façades maximise natural daylight into Broadgate Circle below but presented a significant challenge for the roof construction. Radmat’s ProTherm Quantum® PLUS+ Vacuum Insulation Panel (VIP) inverted roof system was selected to deliver exceptional thermal performance within an extremely shallow build-up. Bespoke ProTherm XPS Infill sections were precision-cut to accommodate the building’s complex geometry and sweeping curves.

80mm ProTherm Quantum insulation was used to achieve U-values as low as 0.11 W/m²K. This enabled level access details to be maintained while helping to offset the performance limitations of other insulated areas. As the terraces required increased green roof substrate depths it was essential that the insulation build-up remained as low as possible. ProTherm Quantum® PLUS+ was installed across multiple roof levels, with meticulous attention given to panel layouts and junction detailing. At Level 8 in particular, where the roof follows the curvature of the façade below, the insulation arrangement was carefully staggered and facetted to accurately follow the changing geometry while maintaining continuous thermal performance.

20,000 sq ft of rooftop terraces and gardens required tried and trusted waterproofing, hence Radmat’s PermaQuik Hot Melt Bitumen Waterproofing System was chosen due to its toughness and reliability for green roofs. It is installed with zero falls and certified for ‘the lifetime of the building’. PermaQuik was also applied to many of the floor levels including the base of the Fulcrum Sculpture to ensure its longevity. It was decided to lower the Fulcrum insitu to preserve the integrity of the sculpture. This not only presented an engineering challenge but also a significant logistical challenge as it was in the centre of the main pedestrian exits to the station that couldn’t be closed. The addition of PermaQuik to the base will ensure it is waterproofed and secure for many years to come

For areas requiring complex detailing, Radmat’s ReadySeal Liquid Applied Waterproofing System provided a seamless, fully bonded solution, complementing the primary waterproofing system and ensuring continuity across intricate interfaces.Together, Radmat’s advanced insulation and waterproofing systems enabled the architectural vision for 100 Liverpool Street to be realised without compromise, delivering outstanding thermal efficiency, long-term durability and waterproof protection for one of London’s most ambitious commercial developments.

Ilona Rose House with its unusual rose-coloured 3D printed façade is a new-build, mixed-use project spread over 13 floors, including a 4 storey, basement with a quarter natural light. It has transformed the former site of the famous Foyles bookshop on Charing Cross Road, boasting outstanding new shops and restaurants, along with new pedestrian walkways, public realm and roof terraces.

The unique building has been designed by MATT Architecture for main contractors Sir Robert McAlpine and offers 150,000 sq ft of office space, 20,000 sq ft of retail fronting on Charing Cross Road and a brand-new public courtyard with 15,000 sq ft of restaurant and bar space.

The upper floors comprising of offices exploit the stepped massing of the building to create over 12,000 sq ft of planted external terraces for the benefit of the occupiers and to enhance the environment.

The south-west facing terraces, nicknamed ‘the hanging gardens of Soho’ will provide external amenity space for every single level of office. It is here that Radmat’s waterproofing and insulation products were chosen for their tried and trusted properties. PermaQuik Hot Melt Bitumen Waterproofing System was used on 95% of the roof areas, multiple roof terraces, Greek Street Tunnel and James’ Courtyard.

EshaFlex Reinforced Bitumen Membrane System was used where a warm roof build up was more suitable.

ReadySeal Liquid Applied System was used on balconies, terraces and detailing where cold applied waterproofing was more suitable.

To meet the 0.13W/m²K U-value requirement within the available 120mm insulation zone, ProTherm Quantum^® PLUS+ Hybrid was used in a zero falls application to all terraces, providing level threshold access between internal and external spaces.

Ilona Rose House has a achieved a BREAM Excellent rating. The contractors and architects worked in close collaboration with Westminster City Council to produce a building with the greenest possible credentials of its time whilst maintaining the required degree of architectural quality. Radmat Building Products helped to achieve this rating with the thinnest possible insulation solution and waterproofing materials guaranteed to last the ‘design life of the building’.