RSHP Revitalizes 1970s Office Building in St James Conservation Area
The 1970s office building in London's St James Conservation Area has been given a new lease of life by RSHP. Surrounded by Grade I and II-listed buildings, including the 19th-century Carlton House Terrace, the project aimed to add four floors of office space while preserving the original structure. The initial plan was for a full redevelopment, but RSHP's careful analysis revealed a more sustainable approach: retaining 55% of the original fabric by repurposing the superstructure and basement.
The brief required increasing floor area and enhancing tenure flexibility. RSHP achieved this through a new linear 'insert' core, seamlessly integrating the 1990s and 1970s sections. At the heart of the building is a double-height reception area, featuring a fully glazed lift group and a new atrium. Rooftop terraces on the new floors offer breathtaking views of St James' Park and Trafalgar Square.
Strategic removal of columns at lower levels and column-free spans at upper floors maximize interior space, all served by an all-electric servicing system. Externally, the Portland stone façade, respecting the Georgian Nash terrace, has been partially retained and restored, with new and enlarged glazing added. The basement car park has been transformed into flexible-use accommodation, including a canteen and presentation rooms, naturally lit by its perimeter and a new atrium rooflight.
The lightweight roof extensions complement the existing structure, providing a sightline from Parliament Hill to the Palace of Westminster. Archive drawings guided the restoration of lost 1970s elements, including the reinstatement of a missing column in the street colonnade.
RSHP's architects shared their vision: Graham Stirk, senior design director, emphasized the project's organizational clarity, creating a harmonious extension within the historic context. Daniel Wright, associate director, highlighted the balance between preserving the original building's merit and rethinking its organization, ensuring a sustainable and functional space. Developers Clivedale and Altius Real Estate praised the project, with Ed Blake and David Laycock commending the retention of the original structure and the exceptional headquarters building it offers.
The project's environmental performance is impressive, with an Energy Performance Certificate rating of B, an embodied carbon of 376 kgCO2eq/m2, and a predicted design life of 60 years. The project's completion in April 2025 marks a significant milestone in London's architectural landscape, showcasing RSHP's expertise in preserving history while embracing modern innovation.
