Foster + Partners to retrofit Westminster offices for US tech billionaire
The scheme has been designed for the Ellison Institute of Technology (EIT), which was set up by Larry Ellison – co-founder of tech giant Oracle – who bought the 11-12 St James’s Square buildings off Chinese Estates for £163 million in late 2024.
Foster + Partners’ plans include retrofitting the existing historic buildings and demolishing features such as a 1980s rear extension, while retaining 66 per cent of the existing structures overall.
A consultation on the plans, which have just been lodged with Westminster City Council, said the 18th and 19th century buildings had become outdated and had been upgraded poorly, with low-quality modern elements undermining their heritage features.
Number 11 St James’s Square was built by Benjamin Timbrell in 1736. Its façade was altered in 1774 and a new balcony and porch installed in 1877. The original No 12 was constructed in 1674 before being demolished and rebuilt by Thomas Cubbitt in 1836.
The buildings were amalgamated from 1965 onwards, with demolition work at the back taking place before a new office extension was built to link them. In 1987 a six-storey residential extension was added.
Fosters’ plans include demolition of a modern two-storey extension at the rear of number 12 and removal of its modern core, which it said will help uncover and restore historic façades at number 11.
Foster + Partners’ proposals for 11-12 St James’ Square – January 2026
A new rear façade ‘that responds to and enhances the character of the site and surrounding Conservation Area’ is proposed, along with a revamp of the buildings’ roofs.
Other plans include façade restoration with ‘accurate paint tones’ to match the original Georgian appearance.
The practice also wants to: reinstate laylights in their original design and position and remove an unsympathetic skylight at number 12, replacing it with a historically correct fanlight; remove 1990s fibreglass statues and replace them with Coade stone ones; and remove modern and inappropriate materials from its roof and replace them with Flemish bond brickwork.
Consultation documents state the project will create ‘high-quality, wellbeing-led office space, securing the long-term future of the buildings while protecting and improving the site’s unique heritage assets’ through its ‘thoughtful, heritage and sustainability-led design’.
Donald Insall Associates is acting as heritage consultant on the job and Avison Young as planning consultant.
In 2023 Piercy&Company, working with Purcell, submitted plans for a refurbishment of the buildings, including improved entrances, for then backer Knightlights Property International. The application was later withdrawn.
EIT was set up by US tech billionaire Ellison – briefly the richest man in the world – to ‘solve pressing challenges’ in the science and tech fields, including in health, medical science, food security, clean energy and AI.
Foster + Partners’ second phase plans for Ellison Institute of Technology campus (October 2025)
Its main UK base is in Oxford, and it opened a London office at 11-12 St James’s Square in November.
Foster + Partners is already working with the EIT on major new laboratories at the Oxford Science Park, and unveiled plans for a second phase of development on nearby land last year.
The campus extension proposals include a new train station at Littlemore on the Cowley branch line.
Westminster Council adopted a retrofit first policy earlier this month, requiring developers to fully explore ‘all reasonable options for retrofitting and adapting existing buildings before seeking permission for demolition and redevelopment’.
The move came six and a half years after the AJ launched its climate-focused RetroFirst campaign for the reuse of existing buildings.
