Construction is due to start on site in 2026 once detailed design is complete and planning conditions met.  The work is expected to take around six years to complete.

Mace fought off competition from McAlpine and Multiplex to land the high profile job.

Mace will join the project under the direction of development manager Stanhope Plc and will contribute construction expertise for the procurement and delivery phase of the development.

Plans include a 100,000 sq ft extension to the British Library comprising new spaces to enhance the Library’s public service offer, provide more than 600,000 sq ft of commercial facilities and integrate Crossrail 2 infrastructure.

The project includes exhibition galleries, events spaces and learning facilities.  Located at the heart of London’s Knowledge Quarter, the development will incorporate circulation areas to connect it with the existing Library building and provide easy access from all directions through the enhanced facility.

It will also include provision to extend the Library’s business offer, with maker spaces to create and pilot products.  The Library is launching a major fundraising campaign to bring these areas to life.

Jason Millett, Mace Group Chief Executive said: “We are delighted to be selected as Construction Manager for the British Library development proposals.  This is a high-profile project with international significance and Mace’s long-established expertise and track record in delivering other major schemes make us well placed for this role.”