Towering over London’s skyline at 225 metres, the RSHP designed Leadenhall building is currently the fourth tallest building in the UK. The skyscraper joins a growing cluster of buildings in the City of London’s financial district including the Gherkin, 20 Fenchurch street (the walkie talkie) and the Lloyds building.

AF/ArmaFlex insulation was left exposed, as an integral part of the deisgn in revealing the full height of the space and exposed steelwork

Located on the 14th floor of the Leadenhall Building, the new Rogers Stirk Harbour + Partners studio  accommodates all of its 200 staff on one floor, helping to promote communication and collaborative working. The fit-out design was undertaken in-house and the structure of the soffit and ducting is exposed to give a greater sense of space and height. The smooth black surface of the ArmaFlex insulation is also left exposed as an integral part of the building services. 

An insulation thickness of 19mm was used to optimise system efficiency, minimising heat losses when supplying warm air heating and keeping the duct work surface temperature above the dew point when used for cold air circulation. The closed cell structure and high water vapoour resistance factor of ArmaFlex serves to prevent moisture ingress, whilst the low thermal conductivity value stops heat losses to fulfil both the hot and cold air HVAC system requirements.

The flexible nature of the product means ArmaFlex can be easily cut to size to fit ducting panels and  moulded around ribs and grilles.
The construction of the Leadenhall building was a pioneering feat. Rather than using a traditional concrete core, an external steel frame was used, more commonly used on bridges and offshore oil rigs. The frame, which is incorporated into the building’s exterior design, is the tallest in the world.

The distinctive slanted design of the building was born through the City of London Corporation’s request that the view of St. Pauls Cathedral from Fleet Street must not be obscured by a new building. The resulting wedge shape of the project lead it to being dubbed the ‘Cheesegrater’.