The Hobhouse Estate project was successfully agreed through a negotiated second stage tender with Deloitte as project manager.
The design includes 20 high-end apartments, offices and retail.
The redevelopment also foresees the return of the prestigious Royal Watercolour Society to their original home.
Osborne was invited to the project as a result of the successful delivery of the £22m Mercers Yard mixed use development in Covent Garden, where Deloitte was also involved.
Following demolition down to ground level, the new structure will be built over existing load bearing listed vaults.
Ron Moir, Osborne Construction board director said; “There was a strong teamwork ethos and partnering approach with the Hobhouse customer, Alaska Developments and Deloitte to overcome a series of challenging constraints that included confined logistics, occupied properties fronting the internal court, the listed vaults and a complex 3D façade geometry.”
Osborne has appointed TPBennett architects and novated Thornton Tomasetti on structures and Max Fordham on services.