Architecture: How the Big Bang created a City of Dinosaurs: In the Eighties it was build, build, build. Now the hi-tech dealing rooms are closed and huge empty towers shadow London's streets, says Martin Pawley

What must be the strongest dose of architecture to reach our television screens since Christopher Martin's A Vision of Britain is to be broadcast on Saturday. Martin's 1989 film, with its famous opening shot of Prince Charles brooding in the royal train about the future of his future kingdom, embraced the whole of the country and culminated in a plea for modest developments and endless care over facades, rooflines, vistas and history in town and village alike. But Masters of the Universe: the men who rebuilt the City (on BBC 2 at 9.35pm on 2 January) focuses on one urban district: the Square Mile and the satellites that have sprung up round it.

This is a remarkable film about the politics, the men, the money and the architecture of the Eighties property boom, produced and directed by Bill Eagles, who cut his teeth on the campaigning series Rough Justice. It chronicles the rise and stall of the 20 million sq ft of financial-services building that took place in London during the Big Bang boom of the Eighties, when expansion was the name of the game and London was trying to maintain its position as one of the world's three leading financial centres.

It is an extraordinary tale of massive building schemes that seem now to be misconceived and energy-guzzling machines. They were sold by the developers to the public and the planners as glistening financial power-houses that would switch the economy into overdrive, and form the cornerstones of an acropolis of art and enlightenment. But the recession destroyed the dream and turned the giants into dinosaurs.

One developer says it was a 'business/cultural revolution' during which you could borrow pounds 100m to put up a building and have 'about the headiest experience you can have in your life'. Another admits: 'If a parent did to a child what we have done to the City since the war, you would go to jail for life.'

In the five years covered by Eagles's film (1985-89), more than 40 state-of- the-art electronic office buildings were erected to serve the financial centre. Most sit on the borders of adjoining boroughs; the established financial district around the Bank of England and Lombard Street was protected by conservation laws and the sheer quality of the buildings, which priced them beyond the reach of speculators.

Seven years ago Margaret Thatcher mounted a digger, broke ground for Broadgate - a huge development of offices, shops, restaurants and public spaces on the site of the old Broad Street station - and announced that the new City architects were following in the footsteps of Sir Christopher Wren, Robert Adam and Inigo Jones. Today, their over-grown, air-conditioned chickens have come home to roost.

As a result of overbuilding, many of the schemes are mothballed and empty, or sparsely populated. Alban Gate, the office tower straddling London Wall designed by Terry Farrell for the developers MEPC, for instance, and One America Square, designed by Renton, Howard, Wood & Levin in Fenchurch Street, were both built with enormous gusto and confidence; neither is a bad building, but neither has fulfilled its promise. The bright illumination, expensive heating and air-conditioning systems idle like jet engines on a runway, waiting for a hand on the throttle that may not come for years.

Ironically, the listed buildings around the Bank of England have also suffered. Emptied by the recession, some are now little more than picturesque shells. The City may have protected them from redevelopment, but it failed to prevent the shift of the financial-services industry to Fleet Street, Victoria, Hackney, Islington and the Isle of Dogs.

Eagles tells the story of this dissipation with cinematic montages of such visual power that it is easy to forget it is a record of urban catastrophe. Through awe-inspiring use of time-lapse photography, the City streetscape heaves and erupts into new forms, while the principal actors in the drama give their own self-exculpatory accounts.

Stuart Lipton, of Stanhope properties, one of the pair of developers which built Broadgate (the other company, Godfrey Bradman's Rosehaugh, was put in the hands of the receiver a month ago), is interviewed in his office in Berkeley Square, seated next to a row of modern sculptures. He talks about the provision of 4 million sq ft of electronic offices around Liverpool Street station as though it had been a Medici- style exercise in artistic patronage.

Michael Cassidy, chairman of the City of London Policy and Resources Committee, drives his Porsche 944 from the Barbican through the uncompleted grand avenue of London Wall, passing under Alban Gate. He powers on to the part-medieval, part-Star Wars metropolis, all the while gazing inscrutably through the reflections of his handiwork rolling past on his windscreen.

In another surreal scene, Peter Rees, then and now chief planning officer of the City of London, dives into a marble swimming pool and propels himself through the water.

'Quality' is a word he uses often, along with 'balance', 'visual interest', 'variety' and 'confidence'. Messrs Rees, Cassidy, Lipton and the other developers whom Eagles interviewed are remarkably self-possessed. These are the men whose towering ambitions enabled them to transform the City and its environs. They rode the tide of money that flooded London in the heyday of Mrs Thatcher's government and today, despite the recession, they still have the look of men who are swimming, not drowning. They saw themselves as latter day Thomas Cubitts (the Regency creator of Belgravia and the greatest of all London's property developers), rebuilding the capital on a tremendous scale in handsome materials.

Yet, as the camera penetrates the empty floors of the old Mappin and Webb building at Mansion House and the derelict banking halls of Old Broad Street and Threadneedle Street - deserted on completion of the NatWest Tower - it is obvious that what remains is an empty shell: a vast space behind facades, some ancient, some modern.

What the programme shows us is a nightmare of building obsolescence for the years ahead. It is, therefore, remarkable that the City Corporation is considering several more major schemes for office blocks by big name architects - such as Sir Norman Foster, who has been commissioned to design a tall glass tower on the site of the old Spitalfields market facing Broadgate. It seems as if the recession is nothing more than an inconvenient blip on the titanic and inexorable horizon of the masters of the universe.

(Photographs omitted)