Common law set 5 King's Bench Walk is to move out of the Temple, ending a 51-year association with the historic Inns of Court.
Practice manager Penny Cook said the move a quarter of a mile north to 18 Red Lion Court, a 17th-century building on Fleet Street, had been forced on the 14-silk set because it had overflowed into an annexe at Mitre Court, making life difficult for clerks.
She added: "We don't want to leave; we love our building here. The reason for our move is that we opted to all go under one roof."
The new building will have about 24 rooms and house 50 barristers, including 14 silks, and 10 staff. A chambers in Chelmsford will be retained.
Cook said the move to Fleet Street was an opportunity to offer improved facilities and services.
The building, which the set will officially leave on 16 May, is to undergo extensive structural repairs, because, like other London buildings, it has suffered from subsidence.
A number of sets are already understood to be eyeing the vacant space.