Whenever architectural 'visionaries' start talking about building utopia, you know you're on very slippery ground. Well, the Slovenian architect-turned-artist Marjetica Potrc is not only thinking of building utopia, she's also apparently already found it.

Her installation at the Barbican's Curve, Forest Rising, is not just inspired by the improbable architectural designs of Dutch artist Constant Nieuwenhuys (who envisaged multi-level cities elevated on stilts) but by an actual, largely self-sustaining native community in Acre, Brazil's western-most state.

On the walls, Potrc has produced colourful cartoons with mantra-like statements: 'We are the doers, the thinkers of the 1960s were dreaming about us'; 'Happiness is to grow in small steps. We have learned to want less.' But we never hear any members of this rainforest community talk about their lives. We just get a video of Potrc - who spent a short residency in Acre - and the curator of last year's Brazil biennial making smug assumptions about how this community works.

With her solar-panelled 'school' on stilts above a forest of trees - surely only functional if you have two pupils - Potrc has resurrected 1960s idealism and tagged it on to environmental concerns of the day.

But somehow it seems very doubtful whether any of the people living there imagine they're living the hippy dream.

Until Sep 2, The Curve, Barbican Centre, Silk Street EC2, daily 11am to 8pm, free.
Tel: 0845 120 7550. Tube: Barbican/Moorgate