With the electrics being dismantled today at Bush House, central London HQ of the BBC World Service for 70 years, Sir John Tusa, its former MD (and chairman of The Arts Desk) presents a Radio 4 programme of memories of radio broadcasts from the building on Sunday, Goodbye to Bush House.

The World Service's move to the refurbished Broadcasting House in Portland Place to join the rest of BBC News completes a historical circle, since the BBC's first foreign services began back at Broadcasting House in 1938. But two years into the Second World War, bombs damaged Broadcasting House and the European Services moved into Bush House, one of London's most imposing Twenties buildings.

Bush House was originally built 1923-5 by an American trading organisation headed by Irving T Bush (after whom it was named), to serve as a massive Anglo-American trade centre at a cost of $10million - it was declared the most expensive building in the world, made of Portland stone and containing a swimming pool.

Its architect was Harvey Wiley Corbett, a champion of skyscrapers who had previously built the 30-storey Bush Tower in Manhattan and would also be involved in the Rockefeller Centre. The symbolism of Anglo-American friendship was emblazoned on the portico (pictured above, © Nigel Cox) with two male statues by the eminent American sculptor Malvina Hoffman, a student of Auguste Rodin, and the inscription "Dedicated to the friendship of English-speaking peoples" over a Celtic altar.

Among key broadcasts transmitted from Bush House were the first Royal Christmas message, from King George V to the Empire in 1932, and General de Gaulle's rallying cries to the Free French after the Germans invaded France in 1940. There is said to be a ghost.

Although the BBC never owned the building, its overseas radio services gradually took Bush House over until by 1958 the entire World Service had colonised it. Its current lease expires this November. Owned variously by the Post Office, the Church of Wales and now a Japanese property company, Kato Kagaku, Bush House is to be refurbished over the next two years for new office accommodation.

• Goodbye to Bush House is on Radio 4 FM 1.30pm on Sunday
• The World Service continues to broadcast from Broadcasting House