Although developments to Lincoln’s Inn have been made during each century, this will be the biggest single project since its original construction.

The listed Great Hall and Library, completed in 1845 and 1873 respectively, are buildings of historic importance that form the collegiate heart of the Inn in Bloomsbury.

They will be carefully restored and refurbished as well as building two new extensions to add to the Inn’s educational facilities.

The Great Hall currently houses the Inn’s principal dining hall, member’s common room, associated catering and event facilities, visitor reception and administrative support offices.

Works on the Great Hall will include the reopening of the main entrance door, an upgrade of the kitchen, drainage and damp proofing and the original configurations and finishes will be reinstated and conserved.

Great Hall with new library extension

A 13,000 sq ft two-storey extension will be constructed below ground under the East Terrace of the Great Hall providing lecture theatre and 10 flexible advocacy training rooms.

Graham will also build a four-storey library extension with one floor underground and three above. This will provide step-free access increasing the access to the collection from 30% to 80%.

Rob Joyce, Graham Construction’s London office director, said: “Lincoln’s Inn is a longstanding institution that prepares future barristers for Call to the Bar.

“The conservation and extension works will preserve and enhance the building for future students and add to the vital functions it provides to its members and the judiciary. The restoration of such a significant historic and architectural property requires great skill and makes this a highly rewarding project for our team.”

Work is due to start on site next month with a projected completion for December 2017.