Let's do the show right here – in the café (or the loo)

Site-specific theatre is everywhere. But is it a gimmick?

Chain reaction: 'Sailing on' is set in a ladies' loo

The stage is no longer the rage. Proscenium arches are archaic. Thrust stages aren't, well, thrusting. Even theatre-in-the-round – so (metaphorically) edgy in the Eighties – is, like Jools Holland, looking quaint. These days there's only one thing to be in theatre and that thing is site-specific.

According to The Cambridge Introduction to Theatre Studies, for theatre to be site-specific, location must provide a semantic frame: the performance space must be integral to the meaning. Going by the number of touring productions which call themselves site-specific, the term has come to refer to any play performed outside of a conventional theatrical space. Site-specific theatre has now become the ultimate affirmation of the adage, 'All the world's a stage'.

Thanks to the Birmingham Repertory Theatre's refurbishment, their forthcoming autumn/winter season is dominated by site-specific theatre. These include a series of short plays by young British East Asian writers, Dim Sum Nights, staged in a Chinese restaurant, plus a new play by Jenny Stephens about post-traumatic stress disordered soldiers performed in the Territorial Army Field Hospital. This is the thing with site-specific theatre (issues over poor sight-lines and muffled acoustics aside): it can sometimes end up smacking of gimmickry.

Take the craze for putting on productions in loos: one needs a darn good reason to make an audience spend an extended period of their time sitting in a WC. The Assassination of Paris Hilton, a comedy-thriller staged in the loos of Edinburgh's Assembly rooms justified doing so on the grounds that the Ladies' is as much a place for talking scandal as it is for reapplying mascara.

Even if it's not about the publicity, there's the risk of a company being carried away by a clever conceit – the site can subsume the play. Female theatre company ShadyJane's Sailing On offered up the ghosts of Virginia Woolf and Ophelia ensconced, Moaning Myrtle-style, in the cubicles of a ladies' lav (told you it was a craze). In spite of ShadyJane winning the Edinburgh Fringe's Emerging Theatre Company Award last year, many critics still remained unconvinced by the show and panned it for consisting of little more than a neat initial premise.

Established theatre companies can be just as vulnerable to seduction by false contrivance. Punchdrunk set their 2010 immersive Duchess of Malfi in an abandoned office block, around which the play's audience was allowed to wander. It seems a thrilling idea, yet according to Anna Picard in The Independent on Sunday, it was less compelling theatre than "a ghost train for adults."

Occasionally site-specific theatre can tip over from unhelpful to weird. This April audiences of Playgroup's Berlin Love Tour were taken on a walking tour of Berlin – around Birmingham. German landmarks such as the Brandenburg Gate (or, to the less imaginative, an office in Brindleyplace Square) were pointed out to the bemused spectators. Admittedly it was the gap between people's views of places and the places themselves that was precisely what Playgroup was attempting to interrogate, but still…

There are clearly many superlative practitioners of site-specific theatre –dreamthinkspeak's site-specific Hamlet re-working, The Rest is Silence, is currently playing to great acclaim. But too often site-specific theatre seems to be based on little more than neat contiguity between theatrical subject and performance location. Before a company takes a production outside of a theatre, they should make sure that in doing so they are serving a deeper purpose than locational punning.