The project, designed by architect TateHindle, will see three extra floors built on what will become a seven storey building.
The frontage of the lower four storeys maintains the street line of neighbouring buildings, with the upper levels tiered back. The office entrance will be relocated to make better use of ground floor space and enjoy the benefit of the now pedestrianised and paved Cursitor Street.
Andrew Tate, director of TateHindle, said: “London’s Midtown is going through much change presently.
“The refurbishment, recladding and extension of 35 Chancery Lane will be an important part of the transformation of the area.”