THEATRE / This is a reproduction that will run and run: Jonathan Glancey, Architecture Editor, on the newly restored Theatre Royal, Haymarket, a perfect example of the historically correct

A ticket for 'An Evening with Peter Ustinov', which opened yesterday at the Theatre Royal, Haymarket, buys you a trip down memory lane in more ways than one. There is Ustinov himself, veteran mimic and raconteur, and then the brand new, historically correct restoration of the auditorium of London's only Grade One listed drama theatre.

Look around you. All that glistens really is gold: 2,500 books of 23 3/4 carat gold-leaf lovingly applied by 25 skilled gilders to virtually every surface and decorative detail. 'A quarter of the pounds 1.3m we spent on the building went on gold-leaf,' says John Rowe-Parr, partner of Rowe-Parr Crawford Shores Ltd, the architects of the restoration.

The architects have designed palaces in Kuwait and so are well-versed in the handling of libraries of gold-leaf. 'The theatre certainly needed it,' says Rowe-Parr. 'It was last redecorated in 1904 and the gold leaf has simply worn away from the touch of so many hands.'

'The theatre was in a very grubby state three months ago. I doubt if it had been given a thorough cleaning since it was last restyled by the Edwardian designer Stanley Peach. We cleared half an inch of thick London soot from the nymphs frolicking around the central chandelier alone - historic dirt; perhaps it should have been listed.' Perhaps it should have; after all, everything else has been. As the architects made haste slowly (they had just 13 weeks to carry out a huge programme of works), English Heritage popped in at critical points to ensure that the cleaned, rewired and spruced-up theatre stayed in a time-warp, forever 1904.

But, as the theatre was designed by John Nash (it cost a bargain pounds 18,000 and opened in July 1821) and redecorated at least once more (in 1875) before Stanley Peach made his colourful mark, why not turn the clock back even further. Why stop at 1904? Why not go back to 1875 or even to Nash's decorative scheme of 1821? 'You would have to be very old indeed,' Rowe-Parr says, 'to remember the Theatre Royal pre-Stanley Peach. English Heritage's view is that the 1904 redesign is the one that everyone will know and love.

'We've done everything we can to bring the old decoration back to life. We'd already cleaned up the Corinthian facade five years ago, returning it to the way it looked in 1904; it made sense to carry the Peach design through to the last detail. We even made new wallpaper from the original woodblock. One of our design team is a member of the British Wallpaper Society; he found the original block designed by Peach in the Sanderson archive in Derby.

'We cleaned layers of nicotine from Charles Harker's fruity frescos and we took the chandelier to pieces - 2,412 pieces; I know, I did the counting - and gave it a spring clean. We repaired torn wall paintings with patches of period-style canvas; we got these from India, where canvas is still woven on the same kind of looms Peach would have known in England at the turn of the century.

'All this was costly, but because we were able to manage the contract ourselves and control costs tightly, we came in well under budget. The rest of the money we used to restore the stage-side of the theatre. That was another clear-out, clean-up job. We removed 10 tons of debris left over from old productions from inside the fly-tower.

'We were also able to carry out a computer study of the original Nash beams carrying the weight of sets. This means we have been able to redistribute the weight carried by each particular beam and so spread the load and reduce future wear and tear.

'We restored the theatre's two famous changing rooms, numbers 1 and 10; the former is haunted by the top-hatted ghost of John Buckstone, the theatre's manager between 1853 and 1879 and a favourite of Queen Victoria; the latter is Sir John Gielgud's favourite West End changing room.

'We weren't particularly aware of the Equity campaign for better changing rooms, but we've done our best. These are some of the best in the business.

'The rest of the money went on a concealed stage-lighting system, new seat upholstery and carpets. We worked 24 hours a day, seven days a week; I think you can truthfully call the project a labour of love.' You might also say that the theatre's owner - the Louis I Michaels Group - has had at least a pound of flesh.

Has it been worth all this effort to recreate history? 'Definitely,' says Rowe-Parr. 'It will undoubtedly help the theatre to attract top-class productions, as well as attracting audiences. In any case, we would not have been allowed to do anything else given the building's listed status.'

Daniel Massey - who first acted here 32 years ago in a production of The School for Scandal, and more recently in Heartbreak House in 1992 - says 'acting at the Haymarket, especially in Shaw, Sheridan or Wilde, is like drinking champagne from a flute rather than a shoe. On stage you have the audience gathered right the way around you - there's a lovely architectural harmony between spectator and actor.

'I think it's a lovely gig. It's the best place in the world to do the Classics - the spirit of the Haymarket seems to invite and embellish them. You feel taken right back to the days of Kean and beyond.'

Certainly the trend in the restoration of old theatres has been for the historically correct rather than for imaginative remodelling. The Savoy in London has, after a fire, been brought back to its showy art deco splendour; the Lyceum in Sheffield is grand and richly Victorian once again; Frank Matcham's flamboyant terracotta theatre at Richmond-upon-Thames has returned to its turn-of- century glory days.

Until a few years ago, the trend had been different. On one level, old theatres were upgraded by the addition of often unsightly new technology. The Theatre Royal itself was kitted out with grim stage- lights bolted brutally into the balcony. There were, however, a number of brave attempts to bring theatres up to date without slavish recourse to history: the Royal Exchange Theatre, Manchester is a good example.

Newly built theatres - the National Theatre is the finest example - made a return to the architectural simplicity of the Greek stage. Decoration was abandoned in favour or architectural mass and modern lighting. When the lights went up, the audience itself provided all the animation and decoration needed. Perhaps this still makes good sense for theatres putting on Shakespeare or at the cutting edge of scriptwriting, direction and performance. Arguably, it makes a lot less sense for West End and provincial theatres out to attract popular plays and popular audiences, including tourists.

When carried out convincingly and down to the last detail, historic reproductions can be a delight. The Savoy, the Sheffield Lyceum and the Theatre Royal are three cases in point. Theatres, after all, are all about the willing suspension of audience's disbelief. We go to the theatre to be taken away from the everyday world, whether to a concrete cavern as found in the National or a fin de siecle Aladdin's cave in the beautifully restored Theatre Royal, Haymarket.

'An Evening with Peter Ustinov' is at the Theatre Royal, Haymarket, London SW1 to 14 May. Box office: 071-930 8800

(Photographs omitted)