Is there a more chameleon-like writer than Michael Frayn? Or, to put it another less flattering way, a more inconsistent one? Can it be that the same man who wrote the scorchingly funny Noises Off also wrote the psychologically penetrating Copenhagen? And can it be the same man who wrote either of those who also wrote the earnestly didactic Benefactors?

This 1984 play - whose original West End cast included Brenda Blethyn and whose subsequent Broadway company featured (in a different role) Glenn Close - puts the social policy of modern architecture and housing under the spotlight. It follows an architect, David, as his plans to build a new south London housing estate go ever skyward, but are doomed to remain earthbound.

This professional crisis is played out against the background of the shifting personal relationships of two couples to each other and themselves: David and his wife Jane; and their ex-University pal and now neighbour Colin and his mousily defeated wife Sheila. In observing these fractured, sometime fractious, friendships, Frayn's play is at its liveliest, and gets commensurately edgy, constantly shifting performances from its new company.

But the issue-driven part of the drama has survived less successfully. While talk of skyscrapers being a hazard to low-flying aircraft get an uneasy laugh in this post-11 September time - and a reference to a pair of towers being like two giant tombstones is even more unfortunate - the questions that underline it, about the sorts of communities people want to live in, have not dated. If anything, they have become more pressing, as the housing stock has diminished in London to a crisis level that means key workers can no longer afford to live here. Against that context, however, the play now emerges as idealistic rather than realistic, and preachy rather than pointed.

Nevertheless, in Jeremy Sams' coolly precise production, there's a quartet of beautifully observed performances that raise the stakes as high as they can go from Aden Gillett and Sylvestra Le Touzel as David and his wife Jane, and from Neil Pearson as Colin, who turns into a campaigning enemy against David's skyscraper plans, and Emma Chambers as his wife Sheila who goes to work for David.

While Sams previously directed Frayn's Noises Off at the National, this one looks, in Robert Jones' design, like it's actually set there, amongst the grey breeze block concrete of its South Bank walls. The piece culminates in a visual coup de theatre that articulates in a second what the play has been attempting all night.

- Mark Shenton