Venues: Keeping their heads above water: At the Bridewell Theatre, you can really enjoy a night out on the tiles. Sarah Hemming plunges in at the deep end

Since Britain is an island full of plush theatres resplendent in velvet, it may seem perverse that theatre companies are constantly performing in outlandish places. Turning their backs on the splendour of gold leaf and the convenience of a lighting rig, many groups choose to do their shows in cramped, cold and even downright inclement conditions. Two years ago Mark Rylance risked pneumonia and braved the full flood of a British summer to stage his Tempest in open spaces where significant ley lines crossed; Marcel Steiner consistently cramps his style by staging his shows in a motorcycle sidecar; while Barrie Rutter habitually launches his Northern Broadsides productions in a disused mill.

For some, the choice of venue is specific to the project - Rylance sought to match the magic of the play with the special properties of the places he staged it; for others it represents a consistent philosophy - Rutter deliberately chooses what he terms 'non-velvet' spaces for his Shakespeare productions. But linking them all is the desire to revitalise the experience of going to the theatre by cutting out an automatic audience response to a recognisable setting.

Latest to take the plunge is Breach of the Piece theatre company, which launches a new London venue this month by mounting The Merchant of Venice in a Victorian swimming pool off Fleet Street. This is not as messy as it might sound - the pool has been dry since 1972 - but it brings its challenges. The distinctive acoustics, whiff of chlorine and cold tiles of a public pool are not instantly compatible with a cosy night out.

The first thing that strikes you about the Bridewell, however, is its atmosphere and intimate charm. Built a century ago, the pool is housed in the basement of the St Bride Institute behind St Bride's Church in Fleet Street, but the pitched glazed roof that covers half the pool area means that it is flooded with a soft natural light, while its combination of wrought iron balconies, pillars and staircases give it an inviting assembly of nooks, corners and potential playing spaces.

The sunken pool area itself is covered with wooden flooring (originally put down every winter and raised every summer), that makes for a huge and adaptable playing space. The whole interior has been sympathetically and handsomely renovated to make use of its original features. The lighting box, for example, is installed in one of the changing cubicles that originally housed bathers.

'I think what strikes you is that everywhere you look there's a stage set,' says Carol Metcalfe, the artistic director of Breach of the Piece. 'People keep coming in and suggesting plays that I hadn't thought of - and they all mention something different, because it suggests something different for every person.'

Her own enthusiasm for the space was the catalyst that brought about its conversion. Canon John Oates of St Bride's Church, chairman of the charitable trust that owns the institute, had long nursed a dream to revive the beneficial role in the community for which it was established 100 years ago. In April last year he met Carol Metcalfe and invited her to look at the space. She saw instantly the pool's potential, and staged a production of Much Ado About Nothing in the unadorned area.

'I thought the governors, who might already have doubts about my sanity, might really go over the top if I talked about making the place into a theatre,' Canon Oates says. 'But Carol enabled me to show what was possible here even under the most diabolical conditions. I remember before every performance I went round all the corners with those Haze air fresheners that you're not supposed to use if you're environmentally concerned, and just before the production was to be staged we discovered rats. We were terrified that they were going to walk out on stage at an inopportune moment.'

The production convinced the governors, however, and the rats, smells and dangling wires have now departed to make way for seating, lighting, disabled access and a handsome red and grey colour scheme. The conversion of the building, carried out by Lloyd Leroy Architects, has cost around pounds 400,000. As Canon Oates points out, this substantial financial wherewithal was something of a god-send. Plans to develop the site of the institute as offices collapsed with the crash.

'Meanwhile we were in the process of selling the old Sunday Telegraph building up Farringdon Road. So we gained very substantially - we'd sold that at the very top of the market and the development here was not going to take place. I persuaded the governors here to put the money on deposit and we used the interest to refurbish the institute . . . We still have as much capital as we did when we began.'

The day-to-day running of the Bridewell will be done, as at most fringe theatres, on a wing and a prayer. Carol Metcalfe, who is paid a small retainer by the Institute as artistic director, has an assistant staff of one, while she describes her company as operating 'like all fringe companies, on a loss-share basis'. The group's spring programme consists of two Shakespeares, a Sondheim musical and a new play by Tim Newton, which Metcalfe commissioned by selling a silver tea-set. The space is also available for rent for conferences, classes and other companies, however, and Metcalfe has found its versatility to be one of its strongest assets. Even the acoustics can be adapted to suit the show.

'What got the actors most when we did Much Ado wasn't the smell or the rats,' Metcalfe says. 'It was the fact that you said your line in the middle of the stage and it went 'burbleburbleburble'. At first it seemed alarming . . . but what we've got now is a wonderful variable acoustic. Using curtains, we can have an enclosed space or a big one. We've got an opera group coming and one singer tried the space out and practically broke the glass in the roof - she was delighted. You just bring the wraps in and take the echo down to the right level.'

Metcalfe has plans to use the pool space beneath the movable floor as an orchestra pit and a further dimension of the stage. But will the pool ever be flooded again? Mention water and a gleam appears in everyone's eye, even that of the Canon, who tactfully turns away while Metcalfe answers, rubbing her hands: 'I must say the idea of actually putting water in it again at some stage is very appealing . . .'

'The Merchant of Venice' opens in rep with 'Julius Caesar' on 18 January. The Bridewell, Bride Lane, London EC4 (071-936 3456)

(Photograph omitted)