Hidden in the bowels of Chichester Festival Theatre are the “star dressing rooms”.

To reach them you have to pass through a circular maze of neutral white corridors that staff members who have worked in the building for years struggle to remember.

All six rooms are buried beneath the 1,206-seat auditorium; close enough to hurry back for a speedy costume change or a panicked scuttle up and out to the crowd when a cue-call comes over the internal tannoy system.

Each corridor is decorated with black and white snapshots of players from Patrick Stewart to Tony Britton making theatrical history. Yet the dressing rooms are stark. The message: it’s better to be on stage.

When theatre manager Janet Bakose takes me on a tour of the theatre to see how it’s shaping up after 50 years existence, the in-house PR who has joined us gets twitchy as I pull out a camera.

“Don’t take photos down here,” she shrieks. “It’s not normally like this.

There are no shows at the moment. It’s usually so glamorous. We’ve never had anyone complain.”

Dressing room 0 is the grandest. Two wooden dressers have smallish make-up mirrors with a few unshaded lightbulbs fastened to the sides. The walls are breeze-block and pallid, and the view out through a small row of square windows is on to a car park and tennis courts. Swivel around 180 degrees and there is a basic shower and toilet combo.

Architects Powell & Moya designed the theatre in the 1960s (the theatre opened its doors in 1962), so the place oozes egalitarianism and functionalism.

Pragmatic principles were the driving force behind the diagonal thrust stage: when optician and former mayor Leslie Evershed- Martin decided to build a theatre in a Chichester park after visiting Stratford in Canada to see the Tyrone Guthrie Theatre, his aim was to make democratic theatre.

There was some opposition to Britain’s first modern thrust stage which combined ancient Greek and Roman with Elizabethan theatre design.

“Hope the National Theatre will not look like this,” screamed The Spectator.

Other conservatives argued it was impossible to hear if an actor had his back to your seat – never a problem with a proscenium arch (if you were in the stalls) – and that stratified seating was a commercial necessity.

Evershed-Martin’s dream was even dubbed the “impossible theatre”.

But he had a vision. After visiting the Canadian theatre in a town with a similar population to Chichester, he demanded there be no cheap seats, no limited views, no VIPs.

So it’s a shock to hear Bakose explain how dressing room 0 was named.

“I honestly can’t remember the stars’ names but the politics over who was to be top billing and in dressing room 1 meant we had to create a new dressing room. We moved all the numbers down and created dressing room 0.

“It’s in honour of Laurence Olivier. It meant both stars were equal on the billing. Now the lead is given dressing room 0.”

Bakose leads us on to a row of smaller, shared dressing rooms directly below the pentagon stage surrounded by seats in the auditorium above.

Such is the demand for the anniversary season that in one room seconded box office staff are ripping and packing tickets to be sent to some of the theatre’s 10,000 Friends.

Another room is filled with maintenance staff who’ve decamped for a break during the two week slot they are given once a year to clean the house lights, make repairs and do alterations.

The slot is short because the huge, daunting, open stage is used by community groups and schools, for university degree presentations and rehearsals.

“It’s important that it’s a people’s theatre,” explains Bakose. “That was Leslie’s dream. When people donate time or money they feel a sense of ownership.”

Bakose still sees theatre-goers who used to come when she first started at the box office in 1978. They are as vocal as ever.

“They certainly let us know what they do and don’t like, which is why we know our audience so well.”

Bakose took a job selling tickets at the “special place I instantly fell in love with” on leaving university. She was supposed to stay for a year and join BBC Radio Sussex. But 34 years later she still still pinches herself when she sees the programme.

In her time they’ve built the Festival Theatre’s democratic sister, the “theatre in the round” Minerva (opened April 1989), which is on the site of a former marquee called The Tent, where actors would do impromptu performances as the New Ventures project.

Though she joined for work and has seen eight different sets of artistic directors, she had actually fallen for the place much earlier.

“I came here to play recorder in a primary school festival when I was a schoolgirl.

“I had to play on that stage. I remember being terrified, with parents and other schools in the audience.

“I played the recorder terribly and I think we did one piece. That was enough.”

Bakose cannot remember a better time than the past seven years under current artistic director Jonathan Church and executive director Alan Finch. She calls the current era “a peak”.

“I’ve seen rocky times when audiences have gone away and the box office has slumped.

“Itmakes our 50 years evenmore extraordinary because before the Arts Council supported us this was purely a commercial theatre.

“We had almost 40 years without Arts Council funding.”

Under Church and Finch, box office sales have increased every year.

Last year four shows including Singin’ In The Rain and Sweeney Todd transferred to the West End.

“Crowds are up and the expectation is even higher. Before we didn’t have such a strong autumn programme, but now we are full all the time.”

Having an audience’s trust is key. “And, of course, the anniversary helps.”

For the 50th anniversary season Church has looked back and aims to make more West End transfers.

Highlights include Penelope Keith, who first performed at Chichester in 1977, returning for The Way Of The World, and world premieres by Hugh Whitemore (A Marvellous Year For Plums) and Michael Wynne (Canvas).

Russian playwright Anton Chekov’s Uncle Vanya, starring Roger Allam and Dervla Kirwan, and George Bernard Shaw’s Heartbreak House starring Derek Jacobi, link to the early years.

Indeed, Laurence Olivier, who made Chichester the National Theatre’s first home and was its first director, starred in Uncle Vanya in one of three productions that made its first “festival season”.

Derek Jacobi was in Olivier’s second company of actors and theatre practitioners that powered his National Theatre Company.

The company began at Chichester and its productions were transferred to London’s Old Vic theatre from 1963 while its current home on London’s South Bank was completed.

Between 1962 and 1965 Olivier established a company of actors to produce several shows to run in repertoire using the same ensemble cast. His festival of three shows – thus Chichester Festival Theatre and Festival Season – ran for three weeks.

It was a bold move by Evershed-Martin to ask the upcoming actor Olivier to be his first director but the thespian was available and the founder had deep pockets.

Bakose never saw those Olivier performances but believes recent productions of Enron, Macbeth and The Browning Version are as good as anything that’s gone before.

“Sweeney Todd was the most extraordinary thing I’ve ever seen us do because of the sheer scale. But if I go further back, Underneath The Arches was fabulous. It was the sort of production you didn’t expect to do well and Patrick Garland put it on in his first season in 1981.

“It was about the Crazy Gang and I didn’t know who they were. The original Crazy Gang were still alive and they came to do a cameo.

“It was a big break for Chris Timothy because he was cast as Chesney Allen and Chesney was still alive, so he would also be in the show.

“Every evening it got to the point where Chris would sing Underneath The Arches on a bench and the stage would rotate. When it came back, Chesney Allen was sitting there.

“They had seamlessly switched and there was such emotion in that auditorium. Every single member of staff loved it and we would sneak in to see different bits.”

Coriolanus was Bakose’s first show as a house manager and it was a fitting debut.

Prince Charles stopped by and Judi Dench tripped over in the dock.

“We had to ask if there was a doctor in the house because she had hurt her ankle.

“She was patched up and finished the show.”

The company included Kenneth Branagh.

“I don’t think programme sales have ever been that good. Kenneth Branagh was at his peak. The company was incredible. That set was striking but minimalist.”

Before I leave, Bakose explains that having made it to 50 years, plans are under way for a £22 million refurbishment.

We meet current box office manager James Morgan who says the biggest change over the years is that nowit’s smaller shows rather than the blockbusters the West End wants.

He picks Nicholas Nickleby as the highlight of his 13 years.

“You would get this great camaraderie in the audience because it was two three-and-a-half hour parts and a seven-hour epic.

“It was a brave thing to do by Jonathan in his first season and the show snowballed and came back the following year.

“I have to mention Singin’ In The Rain too. The audience roared like never before.”

Oaklands Park, Chichester Uncle Vanya opens March 30 until April 28. The season runs until October 27.

For more information visit www.cft.org.uk or call 01243 781312.

More from The Guide

The Argus: Daily Echo on Facebook - facebook.com/southerndailyecho Like us on Facebook

The Argus: Foursquare Check in with The Argus and follow our tips on Foursquare