This includes 100,000 sq ft of new library space for culture, learning, research, and business, and 600,000 sq ft of commercial space for scientific businesses.
The extension, planned by Tokyo-based Mitsui Fudosan Co, was given the green light by Camden Council in July 2024.
It is expected to cost £1.1 billion.
Expansion to connect St Pancras and Somers Town with new public routes and entrances (Image: Mitsui Fudosan Co., Ltd.)
The Japanese real estate company is targeting the life sciences sector with its new commercial spaces.
The project will be managed by Stanhope Plc.
By 2032, the British Library site will have expanded galleries, business support facilities, public spaces, and new entrances.
Commercial space is designed for scientific businesses seeking to locate close to the Francis Crick Institute, Alan Turing Institute and other organisations located in London’s Knowledge Quarter.
The design will open up the library on three sides and create new, publicly accessible areas and routes – internally and externally – connecting it to Somers Town and St Pancras.
The planned extension is a big investment for Mitsui Fudosan, which has signed a long lease of the land with SMBL, the library’s development partner.
Stanhope will continue to manage the development.
Takeshi Iwama, chief executive of Mitsui Fudosan UK, said: “I am delighted to confirm the development of the British Library extension project.
“It represents a major milestone in the evolution of an exceptional opportunity.
“We are proud to be investing in the expansion of one of the UK’s most important cultural institutions, as well as continuing to work with community organisations in Camden to ensure that the benefits from this high-profile investment are experienced as much at the local level as they are nationally and internationally.
“We have already acquired significant expertise in the life sciences sector across Japan and the US over almost a decade and will be bringing this to the British Library extension development, our first in this sector in Europe.
“We are confident that the new commercial space at the heart of the King’s Cross Knowledge Quarter – and designed by leading international architectural practice RSHP and engineers Arup – will encourage some of the world’s most ambitious and successful life sciences companies to invest in the UK by the early 2030s.”
Rebecca Lawrence, chief executive of the British Library, said: “I am delighted to announce this significant milestone in our bold ambition to transform the British Library.
“Our partnership with Mitsui Fudosan will enable us to fulfil our long-held vision to extend the library’s site in St Pancras.
“The plans will open up the library even further, creating an expanded national library with state-of-the-art new spaces, harnessing the power of collaboration to build a new public realm linking communities and the Knowledge Quarter and deliver significant investment in the UK.”
David Camp, CEO of Stanhope Plc, said: “Mitsui Fudosan’s decision to fund the British Library extension is both a major milestone for the project and a strong endorsement of the London property market.
“The 600,000 sq ft (55,800 sq m) of commercial space will be flexible enough to suit a broad range of occupiers who will want to be located at the British Library, adjacent to King’s Cross St Pancras and The Francis Crick Institute and at the heart of the Knowledge Quarter.”
Initial works are due to begin next year.
