Star role for The Shed? The Shed is the unalluring name given to a small free-standing, free-form performance space that the National Theatre is knocking up as a temporary replacement for the Cottesloe, which will shortly be radically remodelled as part of a major redevelopment. Standing in the concourse at the front of the NT's main entrance, designed by Haworth Tompkins and paid for (£1.8 million) out of the profits of War Horse on Broadway, The Shed promises a programme of new left-field work, largely created by the young and hungry, and running from April to next February - when the Cottesloe will reopen as the Dorfman and The Shed will be dismantled. This sounds terrific: the open playground that the National has long needed. My only concern is that it might become so successful that no one can bear to part with it (a problem the RSC has suffered from with its wonderful temporary Stratford venue, the Courtyard), and that the Dorfman will seem awfully staid in comparison. Theatres were never meant to be embedded in glass, steel and concrete, and Denys Lasdun's NT architecture has always reminded me more of a nuclear bunker than a fun palace. The more sheds in theatreland the better.