It was 1951, a great year for architecture and design. Nikolaus Pevsner published the first volume of his epic Buildings of England series, for Nottinghamshire. The extravagantly talented Spanish bridge designer, Santiago Calatrava, was born. Indeed, I owe my own existence to the mood of near euphoria that swept the capital as excited visitors to Battersea's new Pleasure Gardens pootled between Far Tottering and Oyster Creek on Rowland Emett's railway.  Meanwhile, back on the South Bank, there was the epochal Festival of Britain. Here Powell & Moya's earthbound Skylon, the model for half a million standard lamps later to appear in suburban lounges, pointed suggestively heavenwards to a technological future that never quite arrived. This 300ft metal structure, like the Britain of 1951, had no visible support nor any very practical purpose. At the festival a very young textile designer called Terence Conran worked on an exhibition stand for British Rayon. Then, on a Waterloo bombsite, the enduring centrepiece of the festival, the Royal Festival Hall, opened on 3 May.  Early next month, it reopens after a heroic refurbishment. While the temporary stuff of 1951 crumbled, the Festival Hall remained. As a structure, it was technically stretched, and maintenance was soon required. It has been buffed up before. In 1964 foyers and terraces were added to the riverside, extending the plan by 30ft. At the same time, poorly judged decorative tiles from 1951 were removed. The latest refurbishment is the work of architecture firm Allies and Morrison. There are new, much-needed, educational facilities, but the majority of their work is a highly ambitious but very subtle rehabilitation of the 1951 original. It is unusual in a normally egomaniacal architectural profession for a leading firm to dedicate itself to such patient revision of someone else's work. I asked Graham Morrison what visitors will notice:  'First impression will be of a restored clarity.' he said. 'The recovered transparency of the main foyer will remind everyone of the concept of the egg of the auditorium raised up in a box. The new works are not radical: they simply help reveal the original design.'  A new outbuilding on the west has liberated 35 per cent more public space. Western roof terraces become an aerial members' bar. Terence's successors, Conran and Partners, have designed a new river-view restaurant, affectionately named after the old Skylon. Interior colours get back to the more polychrome Scandinavian palette. The original carpet pattern has been dutifully copied (the old one dissected into rugs and sold off). There is new lighting, inside and out, by designers Speirs and Major.  Pleasant memories of 1951 bring into sharp contrast the muddle of the Millennium project where for six exciting but dismaying months in 1997 I was creative director - until I flounced out in protest at government-imposed mediocrity. This is not to say the festival was not politicised, only that it was politicised more intelligently. It was a conscious evocation of the Great Exhibition of 1851 of which Disraeli said it 'will be a boon to the Government, for it will make the public forget its misdeeds'. To doubters 1951 was a 'patriotic prank'; to the more supportive it was a 'tonic to the nation'. Brian Aldiss said: 'It has become an ancient enigma which we decode with difficulty.' Maybe, but it brought about great architecture and design. In this it was a marvellous success while the Millennium was a pitiable calamity.  A Festival of Britain was first proposed in 1943; the spirit of national renewal it was intended to capture was prototyped in a 1946 exhibition at the Victoria & Albert Museum called 'Britain Can Make It'. It addressed a nation of bruised but proud survivors, creating an optimistic mood that lasted a generation. It employed great artists. It was directed with energy and flair. A newspaperman called Gerald Barry was in overall charge but he delegated creative responsibility to the talented and ambitious architect Hugh Casson (1910-1999). And Casson worked wonders, leaving stuff that will forever be in the collective imagination.  But in the political background was Herbert Morrison, the son of a Brixton policeman, later cutely known as Lord Festival. He had become part-time secretary of the new London Labour Party in 1914. By 1919 he was Mayor of Hackney and elected to the LCC for East Woolwich in 1922. Morrison chose the South Bank site because it was near to 'his' County Hall. This muscular avatar of Old Labour was grandfather to the Peter Mandelson who became 'Dome Secretary' in the Blair dawn. Clement Attlee said of Morrison that he 'cannot distinguish between big things and little things'. His grandson, on Dome and other activities, could not, alas, distinguish between good and bad.  The Festival of Britain had a budget of £12 million against the Dome's £1 billion. It was publicised by two million leaflets in eight languages. Press ads appeared in 34 countries. Four liveried double-decker buses toured Europe and a converted aircraft carrier, the Campania, carried a floating festival around the nation's ports. Laurie Lee, a former staff member of the Ministry of Information, wrote the captions for 30,000 exhibits. Abram Games, the last master of the drawn lithograph, did the graphics. Casson was free to recruit the best designers in the country, including Misha Black, James Gardner, Ralph Tubbs, James Holland. When I tried to do the same in the Dome (which, coincidentally, has also been redeveloped, and is due to reopen as a vast entertainment venue in July), I was told we could not have foreigners.  In 1951 there was an appetite for quality. Even if, as critic Reyner Banham said, the English were not yet confident enough to enjoy themselves without being told to do so by Herbert Morrison. Blair and Mandelson tried the same 48 years later, telling us to shut up and enjoy patronising rubbish. 'There is no doubt,' the official 1951 publication boomed, 'that those who come will carry back with them a sense of Britain's continuing vitality as a creative force in the world today.' Weirdly, this was true. Robin and Lucienne Day and Ernest Race designed furniture for the Festival of Britain which became the synecdoche of British modernism in the Fifties. The Days designed the seating in the Royal Festival Hall, now happily restored. There was sculpture by Henry Moore, Barbara Hepworth, Lynn Chadwick and Reg Butler. It was a sort of forced march into the future.  There are lessons here. While Fifties modernism is generally reviled, the public retains an overwhelming sense of affection for the Royal Festival Hall. Hitherto, Liverpool's Philharmonic Hall, built by Herbert Rowse between 1933 and 1939, was the only purpose-built concert hall of any ambition in the whole country. Maybe the optimism of its designers was passed on. Hugh Casson gave the job of lead designer to Leslie Martin (1908-1999) of the LCC Architects' Department, only 39 at the time and very taken with the Nordic example of Alvar Aalto and Gunnar Asplund. A 1948 sketch by Martin shows the design of the concert hall as the egg in a box described by Graham Morrison: the auditorium virtually floats in an envelope. But the great thing is the arrangement of interior space: the central staircase has a ceremonial feel and moves elegantly through the different levels of light and air. There is a sense of subtlety and freedom: it is friendly second-generation modernism, as if drawn by Osbert Lancaster.  The concert hall itself was an ambitious container for 3,000 people. The boxes - routinely described as looking like drawers pulled out in a hurried burglary - are cantilevered out in a seemingly arbitrary way, but none has a compromised sightline. The ceiling is wilfully sculptural, a conceit at the very edge of building technology and, as it turns out, way beyond the contemporary understanding of acoustics. But it was a thrilling building. Hugh Casson's daughter, Dinah, herself a distinguished architect and designer, told me: 'I was five when the festival opened. The hall is still fused with a deep sensation, not fully understood, of something very special. Apart from its architectural intelligence, there is a special warmth about it. It was a kind of oasis when everything else seemed to be grey and mean. This wasn't mean, neither was it splashy ... it was like climbing into one of the musical instruments we had come to hear.'  Indeed the 1951 concert hall was designed as an instrument in its own right, but the reach of the acousticians exceeded their grasp. A major element of the Allies and Morrison refurbishment is new acoustics by the American expert Larry Kierkegaard. Performers found the original acoustic 'dry'. Existing materials have been reused; wooden panels removed and relined and replaced. Surfaces intended originally to absorb sound have been recast to support it. Boxes now have integrated speakers. The undulating plaster ceiling panels have been faithfully copied and replaced with better materials. There are new, adjustable acoustic wings over the stage. At a private 'acoustic tuning' event I attended last month, however, the master of ceremonies could not be heard in my box - although Brahms was loud and clear.  The Royal Festival Hall is the country's most romantic modern building. It is a place of interesting memories and many layers, not all architectural. It was host to the Eurovision Song Contest in 1960 (Winner: Jacqueline Boyer's 'Tom Pillibi' for France). In 1964 the same Terence Conran who worked on festival stands opened his first Habitat store and popular taste in home furnishing was forever improved. Conran had been inspired by the Days and Race. The year after Habitat, Peter Mandelson learnt of Herbert Morrison's death not from a concerned parent, but in a television newsflash, an event which psychologists might see as the source of a fatal bonding with the media.  It is instructive to consider why we think so fondly of the Royal Festival Hall. First, it recalls an age of innocent optimism, maintained under hardship, when American poet Kenneth Rexroth could write  'How can they write or paintIn a country where itWould be nicer to beFed intravenously'  Rexroth could, perhaps, not have imagined the Babylon of faddish catering now surrounding Martin's egg-in-a-box.  Second, Leslie Martin's successor at the LCC, fellow Mancunian Sir Hubert Bennett (1909-2000), was in the later Fifties and Sixties forced by politically motivated rehousing targets to build tall, using untried construction materials and systems. The result was the nightmare council high rises that so discredited architecture. It was Bennett's team who, in 1971, finished the South Bank Centre, whose wet and windy concrete ramps now make the Royal Festival Hall look 'almost classical' in critic Ian Nairn's words. It is this elegiac quality that makes the Royal Festival Hall great: it is what modernism was meant to be, but politics prevented.  Mandelson's Dome did not, thinking of Disraeli, make the nation forget his government's misdeeds (although it was quietly dropped from its promised place on the first page of the second Blair manifesto). On the contrary, the Dome is a symbol of all that was wrong with Blair: vapid promises, amateurish management, a squeamish refusal to tackle difficult issues and poll-driven sensibilities. We admire the Royal Festival Hall for the imagination, bravery, confidence and vision of the people who built it, free of political interference. In any year, these are the source of great architecture.  Dinah Casson still says of the Royal Festival Hall: 'I love it and visit as often as I can.' Has anyone ever said that of the pathetic Dome?  The cost of the new  Wembley Stadium, LondonFoster + Partners, HOK Sport, 2007  Begun in 1996 and due for completion for the 2006 FA Cup final, Wembley finally opened yesterday. Total cost: £798m.  Royal Festival Hall redevelopmentLondon Allies and Morrison, 2007  Total cost £91m, including £25m from Arts Council England; £22m from the Heritage Lottery; £5m grant from the Department for Culture. More than £2m raised from audience members.  Bluecoat Arts Centre, LiverpoolBIQ Architecten (Rotterdam), early 2008  A new wing to this 1725, Grade I Listed building will house the contemporary art gallery, performance and artist studio space. Estimated cost: £9.75m.  See a gallery of the new Royal Festival Hall
The Royal Festival Hall, reopening next month after a thrilling yet subtle makeover, is a precious remnant of the festival that put pride back into postwar Britain, writes Stephen Bayley.